http://www.eso.org/sci/libraries/latest-eso-papers.php The Telescope Bibliography (telbib) is ESO's database of refereed papers that use ESO data (public interface: http://www.eso.org/libraries/telbib.html). Developed, maintained, and further enhanced by the ESO Library, telbib is used to generate statistics and reports on a regular basis as well as on request (see for instance Basic ESO Statistics, http://www.eso.org/sci/libraries/edocs/ESO/ESOstats.pdf). For questions and suggestions, please contact the ESO Librarians at library@eso.org en-en http://www.eso.org/sci/libraries/rss/rss.php Rss Feed Engine library@eso.org library@eso.org http://telbib.eso.org/detail.php?id=47993 Instruments: LABOCA
ProgramIDs: 181.C-0885, 078.F-9040, 079.C-9501, 081.C-9501, Chilean data
BibCode: 2013MNRAS.431.1752U

Using the 870 μm APEX Telescope large area survey of the Galaxy, we have identified 577 submillimetre continuum sources with masers from the methanol multibeam survey in the region 280° < ℓ < 20°; |b| < 1°.5 94 per cent of methanol masers in the region are associated with submillimetre dust emission. We estimate masses for ˜450 maser-associated sources and find that methanol masers are preferentially associated with massive clumps. These clumps are centrally condensed, with envelope structures that appear to be scale-free, the mean maser position being offset from the peak column density by 0 ± 4 arcsec. Assuming a Kroupa initial mass function and a star formation efficiency of ˜30 per cent, we find that over two-thirds of the clumps are likely to form clusters with masses >20 M&sun;. Furthermore, almost all clumps satisfy the empirical mass-size criterion for massive star formation. Bolometric luminosities taken from the literature for ˜100 clumps range between ˜100 and 106 L&sun;. This confirms the link between methanol masers and massive young stars for 90 per cent of our sample. The Galactic distribution of sources suggests that the star formation efficiency is significantly reduced in the Galactic Centre region, compared to the rest of the survey area, where it is broadly constant, and shows a significant drop in the massive star formation rate density in the outer Galaxy. We find no enhancement in source counts towards the southern Scutum-Centaurus arm tangent at ℓ ˜ 315°, which suggests that this arm is not actively forming stars. ]]> http://telbib.eso.org/detail.php?id=47993 http://telbib.eso.org/detail.php?id=48002 Instruments: HARPS
ProgramIDs: 072.C-0488
BibCode: 2013A&A...552A.103R

Stellar activity signatures such as spots and plages can significantly limit the search for extrasolar planets. Current models of activity-induced radial velocity (RV) signals focus on the impact of temperature contrast in spots according to which they predict the signal to diminish toward longer wavelengths. The Zeeman effect on RV measurements counteracts this: the relative importance of the Zeeman effect on RV measurements should grow with wavelength because the Zeeman displacement itself grows with λ, and because a magnetic and cool spot contributes more to the total flux at longer wavelengths. In this paper, we model the impact of active regions on stellar RV measurements including both temperature contrast in spots and line broadening by the Zeeman effect. We calculate stellar line profiles using polarized radiative transfer models including atomic and molecular Zeeman splitting over large wavelength regions from 0.5 to 2.3 μm. Our results show that the amplitude of the RV signal caused by the Zeeman effect alone can be comparable to that caused by temperature contrast; a spot magnetic field of ~1000 G can produce a similar RV amplitude as a spot temperature contrast of ~1000 K. Furthermore, the RV signal caused by cool and magnetic spots increases with wavelength, in contrast to the expectation from temperature contrast alone. We also calculate the RV signal caused by variations in average magnetic field strength from one observation to the next, for example due to a magnetic cycle, but find it unlikely that this can significantly influence the search for extrasolar planets. As an example, we derive the RV amplitude of the active M dwarf AD Leo as a function of wavelength using data from the HARPS spectrograph. Across this limited wavelength range, the RV signal does not diminish at longer wavelengths but shows evidence for the opposite behavior, consistent with a strong influence of the Zeeman effect. We conclude that the RV signal of active stars does not vanish at longer wavelength but sensitively depends on the combination of spot temperature and magnetic field; in active low-mass stars, it is even likely to grow with wavelength. ]]> http://telbib.eso.org/detail.php?id=48002 http://telbib.eso.org/detail.php?id=47909 Instruments: FEROS2.2, HARPS
ProgramIDs: 076.D-0172, 077.D-0477, 084.D-0338
BibCode: 2013A&A...553A..27K

Aims: Time series of high-resolution spectra of the late B-type star HD 11753 exhibiting HgMn chemical peculiarity are used to study the surface distribution of different chemical elements and their temporal evolution. Methods: High-resolution and high signal-to-noise ratio spectra were obtained using the CORALIE spectrograph at La Silla in 2000, 2009, and 2010. Surface maps of Y ii, Sr ii, Ti ii, and Cr ii were calculated using the Doppler imaging technique. The results were also compared to equivalent width measurements. The evolution of chemical spots both on short and long time scales were investigated. Results: We determine the binary orbit of HD 11753 and fine-tune the rotation period of the primary. The earlier discovered fast evolution of the chemical spots is confirmed by an analysis using both the chemical spot maps and equivalent width measurements. In addition, a long-term decrease in the overall Y ii and Sr ii abundances is discovered. A detailed analysis of the chemical spot configurations reveals some possible evidence that a very weak differential rotation is operating in HD 11753. Based on observations obtained with the CORALIE Échelle Spectrograph on the 1.2-m Euler Swiss telescope, situated at La Silla, Chile; based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programmes 076.D-0172 and 077.D-0477; and based on data obtained from the ESO Science Archive Facility under request number HHKorhonen15448.Table 2 is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (<ext-link ext-link-type="ftp" xlink:href="ftp://130.79.128.5">130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/553/A27Table 1 and Figs. 12-19, 22, and 23 are available in electronic form at http://www.aanda.org ]]> http://telbib.eso.org/detail.php?id=47909 http://telbib.eso.org/detail.php?id=47919 Instruments: SINFONI
ProgramIDs: 179.B-0261
BibCode: 2013MNRAS.431.2789S

The central parsec of the Milky Way is a very special region of our Galaxy; it contains the supermassive black hole associated with Sgr A* as well as a significant number of early-type stars and a complex structure of streamers of neutral and ionized gas, within two parsec from the centre, representing a unique laboratory. We report the identification of a high velocity compact nebular filament 2.2 arcsec south of Sgr A*. The structure extends over ˜1 arcsec and presents a strong velocity gradient of ˜200 km s-1 arcsec-1. The peak of maximum emission, seen in [Fe III] and He I lines, is located at dα = +0.20 ± 0.06 arcsec and dδ = -2.20 ± 0.06 arcsec with respect to Sgr A*. This position is near the star IRS 33N. The velocity at the emission peak is Vr = -267 km s-1. The filament has a position angle of PA = 115° ± 10°, similar to that of the Bar and of the Eastern Arm at that position. The peak position is located 0.7 arcsec north of the binary X-ray and radio transient CXOGX J174540.0-290031, a low-mass X-ray binary (LMXB) with an orbital period of 7.9 h. The [Fe III] line emission is strong in the filament and its vicinity. These lines are probably produced by shock heating but we cannot exclude some X-ray photoionization from the LMXB. Although we cannot rule out the idea of a compact nebular jet, we interpret this filament as a possible shock between the Northern and the Eastern Arm or between the Northern Arm and the mini-spiral `Bar'. ]]> http://telbib.eso.org/detail.php?id=47919 http://telbib.eso.org/detail.php?id=47889 Instruments: FORS2, VIMOS
ProgramIDs: 088.D-0974, 386.D-0995, 284.D-5008
BibCode: 2013ApJ...768L..22S

We studied the optical spectrum of HLX-1 during its latest outburst, using the FORS2 spectrograph on the Very Large Telescope. We detect an Hα emission line centered at λ = 6718.9 ± 0.9 Å and find that its projected radial velocity with respect to the nucleus of ESO 243–49 is 424 ± 27 km s–1, while the maximum rotational velocity of the stars in that galaxy is ≈209 km s–1. This suggests that HLX-1 and its surrounding stars were not formed in situ, but came either from a disrupted dwarf galaxy or from a nuclear recoil. We also find that the Hα emission line is resolved with FWHM ≈400 km s–1, suggesting a nebular rather than disk origin for the emission. Its luminosity (L Hα ≈ a few 1037 erg s–1, equivalent width ≈70 Å) is also consistent with emission from a nebula photoionized by HLX-1. ]]> http://telbib.eso.org/detail.php?id=47889 http://telbib.eso.org/detail.php?id=48003 Instruments: VIRCAM
ProgramIDs: 179.B-2002
BibCode: 2013A&A...552A.101S

The new multi-epoch near-infrared VISTA Variables in the Vía Láctea (VVV) survey is sampling 562 deg2 of the Galactic bulge and adjacent regions of the disk. Accurate astrometry established for the region surveyed allows the VVV data to be merged with overlapping surveys (e.g., GLIMPSE, WISE, 2MASS, etc.), thereby enabling the construction of longer baseline spectral energy distributions for astronomical targets. However, in order to maximize use of the VVV data, a set of transformation equations are required to place the VVV JHKs photometry onto the 2MASS system. The impetus for this work is to develop those transformations via a comparison of 2MASS targets in 152 VVV fields sampling the Galactic disk. The transformation coefficients derived exhibit a reliance on variables such as extinction. The transformed data were subsequently employed to establish a mean reddening law of EJ-H/EH-Ks = 2.13 ± 0.04, which is the most precise determination to date and merely emphasizes the pertinence of the VVV data for determining such important parameters. Based on observations taken within the ESO VISTA Public Survey VVV, Programme ID 179.B-2002. ]]> http://telbib.eso.org/detail.php?id=48003 http://telbib.eso.org/detail.php?id=47998 Instruments: VIMOS
ProgramIDs: 175.A-0839
BibCode: 2013MNRAS.431.1090M

We present deep Gemini Multi-Object Spectrograph-South spectroscopy for 11 galaxy groups at 0.8 < z < 1.0, for galaxies with rAB < 24.75. Our sample is highly complete (>66 per cent) for eight of the 11 groups. Using an optical-near-infrared colour-colour diagram, the galaxies in the sample were separated with a dust insensitive method into three categories: passive (red), star-forming (blue) and intermediate (green). The strongest environmental dependence is observed in the fraction of passive galaxies, which make up only ˜20 per cent of the field in the mass range 1010.3 < Mstar/M&sun; < 1011.0, but are the dominant component of groups. If we assume that the properties of the field are similar to those of the `pre-accreted' population, the environment quenching efficiency (ɛρ) is defined as the fraction of field galaxies required to be quenched in order to match the observed red fraction inside groups. The efficiency obtained is ˜0.4, similar to its value in intermediate-density environments locally. While green (intermediate) galaxies represent ˜20 per cent of the star-forming population in both the group and field, at all stellar masses, the average specific star formation rate of the group population is lower by a factor of ˜3. The green population does not show strong Hδ absorption that is characteristic of starburst galaxies. Finally, the high fraction of passive galaxies in groups, when combined with satellite accretion models, require that most accreted galaxies have been affected by their environment. Thus, any delay between accretion and the onset of truncation of star formation (τ) must be ≲ 2 Gyr, shorter than the 3-7 Gyr required to fit data at z = 0. The relatively small fraction of intermediate galaxies require that the actual quenching process occurs quickly, with an exponential decay time-scale of τq ≲ 1 Gyr. ]]> http://telbib.eso.org/detail.php?id=47998 http://telbib.eso.org/detail.php?id=47997 Instruments: CHAMP+, SHFI
ProgramIDs: Max-Planck data
BibCode: 2013A&A...552A.122B

Context. One of the big questions in astrochemistry is whether complex organic molecules are formed in the gas phase after evaporation of the icy mantles of interstellar dust grains or at intermediate temperatures within these icy mantles. Dimethyl ether (CH3OCH3) is one of these species that may form through either of these mechanisms, but it is yet unclear which is dominant. Aims: The goal of this paper is to determine the respective importance of solid state vs. gas phase reactions for the formation of dimethyl ether. This is done by a detailed analysis of the excitation properties of the ground state and the torsionally excited states, ν11 = 1 and ν15 = 1, toward the high-mass star-forming region G327.3-0.6. Methods: With the Atacama Pathfinder EXperiment 12 m submillimeter telescope, we performed a spectral line survey toward G327.3-0.6 around 1.3, 1.0, and 0.9 mm as well as at 0.43 and 0.37 mm. The observed CH3OCH3 spectrum is modeled assuming local thermal equilibrium. Results: CH3OCH3 has been detected in the ground state, ν= 0, and in the torsionally excited states ν11 = 1 and ν15 = 1, for which lines have been detected here for the first time. The emission is modeled with an isothermal source structure as well as with a non-uniform spherical structure. In the isothermal case two components at 80 and 100 K are needed to reproduce the dimethyl ether emission, whereas an abundance jump at 85 K or a model with two abundance jumps at 70 and 100 K fit the emission equally well for the non-uniform source model. The emission from the torsionally excited states, ν11 = 1 and ν15 = 1, is very well fit by the same model as the ground state. Conclusions: For non-uniform source models one abundance jump for dimethyl ether is sufficient to fit the emission, but two components are needed for the isothermal models. This suggests that dimethyl ether is present in an extended region of the envelope and traces a non-uniform density and temperature structure. Both types of models furthermore suggest that most dimethyl ether is present in gas that is warmer than 100 K, but a smaller fraction of 5%-28% is present at temperatures between 70 and 100 K. The dimethyl ether present in this cooler gas is likely formed in the solid state, while gas phase formation probably is dominant above 100 K. Finally, the ν11 = 1 and ν15 = 1 torsionally excited states are easily excited under the density and temperature conditions in G327.3-0.6 and will thus very likely be detectable in other hot cores as well. Appendix A is available in electronic form at http://www.aanda.org ]]> http://telbib.eso.org/detail.php?id=47997 http://telbib.eso.org/detail.php?id=47996 Instruments: EFOSC2_NTT
ProgramIDs: 088.A-0119
BibCode: 2013MNRAS.431.1019F

We present the discovery of a triplet of quasars at z ≈ 1.51. The whole system is well accommodated within 25 arcsec (i.e. 200 kpc in projected distance). The velocity differences among the three objects (as measured through the broad Mg II emission line) are <1000 km s-1, suggesting that the quasars belong to the same physical structure. Broad-band near-infrared (NIR) images of the field do not reveal evidence of galaxies or galaxy clusters that could act as a gravitational lens, ruling out the possibility that two or all the three quasars are multiple images of a single, strongly lensed source. QQQ J1519+0627 is the second triplet of quasars known up to date. We estimate that these systems are extremely rare in terms of simple accidental superposition. The lack of strong galaxy overdensity suggests that this peculiar system is harboured in the seeds of a yet-to-be-formed massive structure. Based on observations collected at the La Silla Observatory with the New Technology Telescope of the European Southern Observatory and at the Calar Alto Observatory with the 3.5 m telescope of the Centro Astrónmico Hispano Alemán. ]]> http://telbib.eso.org/detail.php?id=47996 http://telbib.eso.org/detail.php?id=47994 Instruments: LABOCA
ProgramIDs: 081.F-9329
BibCode: 2013MNRAS.431.1596G

Low-metallicity galaxies exhibit different properties of the interstellar medium (ISM) compared to nearby spiral galaxies. Obtaining a resolved inventory of the various gas and dust components of massive star-forming regions and diffuse ISM is necessary to understand how those differences are driven. We present a study of the infrared/submillimetre (submm) emission of the massive star-forming complex N158-N159-N160 located in the Large Magellanic Cloud (LMC). Combining observations from the Spitzer Space Telescope (3.6-70 μm), the Herschel Space Observatory (100-500 μm) and Large APEX Bolometer Camera (LABOCA) (on Atacama Pathfinder EXperiment, 870 μm) allows us to work at the best angular resolution available now for an extragalactic source (a few parsec for the LMC). We observe a remarkably good correlation between the Herschel Spectral and Photometric Imaging Receiver (SPIRE) and LABOCA emission and resolve the low surface brightnesses emission. We use the Spitzer and Herschel data to perform a resolved spectral energy distribution (SED) modelling of the complex. Using modified blackbodies, we derive an average `effective' emissivity index of the cold dust component βc of 1.47 across the complex. If βc is fixed to 1.5, we find an average temperature of ˜27 K (maximum of ˜32 K in N160). We also apply the Galliano et al. SED modelling technique (using amorphous carbon to model carbon dust) to derive maps of the star formation rate, the grain temperature, the mean starlight intensity, the fraction of polycyclic aromatic hydrocarbons (PAH) or the dust mass surface density of the region. We observe that the PAH fraction strongly decreases in the H II regions we study. This decrease coincides with peaks in the mean radiation field intensity map. The dust surface densities follow the far-infrared distribution, with a total dust mass of 2.1 × 104 M&sun; (2.8 times less than if carbon dust was modelled by standard graphite grains) in the resolved elements we model. We also find a non-negligible amount of dust in the region called `N159 South', a molecular cloud that does not show massive star formation. We also investigate the drivers of the Herschel/PACS (Photodetector Array Camera and Spectrometer) and SPIRE submm colours and find that the submm ratios correlate strongly with the radiation field intensity and with the near and mid-IR surface brightnesses equally well. Comparing our dust map to H I and CO observations in N159, we then investigate variations in the gas-to-dust mass ratio (G/D) and the CO-to-H2 conversion factor XCO. A mean value of G/D˜356 is derived when using XCO = 7×1020 H2 cm-2 (K km s-1)-1. If a constant G/D across N159 is assumed, we derive a XCO conversion factor of 5.4×1020 H2 cm-2 (K km s-1)-1. We finally model individual regions to analyse variations in the SED shape across the complex and the 870 μm emission in more details. No measurable submm excess emission at 870 μm seems to be detected in these regions. ]]> http://telbib.eso.org/detail.php?id=47994 http://telbib.eso.org/detail.php?id=47988 Instruments: ALMA_Bands
ProgramIDs: 2011.0.00121.S
BibCode: 2013ApJ...768L..38H

We present the first detection of extragalactic submillimeter H2O maser in the 321 GHz transition toward the center of Circinus galaxy, the nearby Type 2 Seyfert using the Atacama Large Millimeter/Submillimeter Array. We find that Doppler features of the detected 321 GHz H2O maser straddle the systemic velocity of the galaxy as seen in the spectrum of the known 22 GHz H2O maser in the galaxy. By comparing the velocities of the maser features in both transitions, it can be deduced that the 321 GHz maser occurs in a region similar to that of the 22 GHz maser, where the sub-parsec-scale distribution of the 22 GHz maser was revealed by earlier very long baseline interferometry observations. The detected maser features remain unresolved at the synthesized beam of ~0.''66 (~15 pc) and coincide with the 321 GHz continuum peak within small uncertainties. We also present a tentative detection of the highest velocity feature (redshifts up to ~635 km s–1) in the galaxy. If this high-velocity feature arises from a Keplerian rotating disk well established in this galaxy, it is located at a radius of ~0.018 pc (~1.2 × 105 Schwarzschild radii), which might probe molecular material closest to the central engine. ]]> http://telbib.eso.org/detail.php?id=47988 http://telbib.eso.org/detail.php?id=47969 Instruments: ISAAC, SOFI
ProgramIDs: 69.C-0175, 076.C-0386
BibCode: 2013ApJ...767..147G

We present a survey of H2 jets from young protostars in the Vela-D molecular cloud (VMR-D), based on Spitzer-IRAC data between 3.6 μm and 8.0 μm. Our search has led to the identification of 15 jets (two new discoveries) and about 70 well-aligned knots within 1.2 deg2. We compare the Infrared Array Camera (IRAC) maps with observations of the H2 1-0 S(1) line at 2.12 μm, with a Spitzer-MIPS map at 24 μm and 70 μm, and with a map of the dust continuum emission at 1.2 mm. From such a comparison, we find a tight association between molecular jets and dust peaks. The jet candidate exciting sources have been searched for in the published catalog of the young stellar objects of VMR-D. In particular, we searched for all the sources of Class II or (preferentially) earlier which are located close to the jet center and aligned with it. Furthermore, the association between jet and exciting source was validated by estimating the differential extinction between the jet opposite lobes. We are able to find a best-candidate exciting source in all but two jets, for which two alternative candidates are given. Four exciting sources are not (or very barely) observed at wavelengths shorter than 24 μm, suggesting that they are very young protostars. Three of them are also associated with the most compact jets (projected length lsim0.1 pc). The exciting source spectral energy distributions (SEDs) have been constructed and modeled by means of all the available photometric data between 1.2 μm and 1.2 mm. From SEDs fits, we derive the main source parameters, which indicate that most of them are low-mass protostars. A significant correlation is found between the projected jet length and the [24]–[70] color, which is consistent with an evolutionary scenario according to which shorter jets are associated with younger sources. A rough correlation is found between IRAC line cooling and exciting source bolometric luminosity, in agreement with the previous literature. The emerging trend suggests that mass loss and mass accretion are tightly related phenomena and that both decrease with time. ]]> http://telbib.eso.org/detail.php?id=47969 http://telbib.eso.org/detail.php?id=47980 Instruments:
ProgramIDs:
BibCode: 2013ApJ...768L...7J

MACHO-97-BLG-41 is a gravitational microlensing event produced by a lens composed of multiple masses detected by the first-generation lensing experiment. For the event, there exist two different interpretations of the lens from independent analyses based on two different data sets: one interpreted the event as produced by a circumbinary planetary system while the other explained the light curve with only a binary system by introducing orbital motion of the lens. According to the former interpretation, the lens would not only be the first planet detected via microlensing but also the first circumbinary planet ever detected. To resolve the issue using state-of-the-art analysis methods, we reanalyze the event based on the combined data used separately by the previous analyses. By considering various higher-order effects, we find that the orbiting binary-lens model provides a better fit than the circumbinary planet model with Δχ2 ~ 166. The result signifies the importance of even and dense coverage of lensing light curves in the interpretation of events. ]]> http://telbib.eso.org/detail.php?id=47980 http://telbib.eso.org/detail.php?id=19321 Instruments:
ProgramIDs:
BibCode: 2000APJ...534..894A

We analyze PLANET collaboration data for MACHO 97-BLG-41, the only microlensing event observed to date in which the source transits two disjoint caustics. The PLANET data, consisting of 46 V-band and 325 I-band observations from five southern observatories, span a period from the initial alert until the end of the event. Our data are incompatible with a static binary lens, but are well fitted by a rotating binary lens of mass ratio q=0.34 and angular separation d~0.5 (in units of the Einstein ring radius), in which the binary separation changes in size by δd=-0.070+/-0.009 and in orientation by δθ=5.61d+/-0.36d during the 35.17 days between the separate caustic transits. We use this measurement, combined with other observational constraints, to derive the first kinematic estimate of the mass, distance, and period of a binary microlens. The relative probability distributions for these parameters peak at a total lens mass M~0.3 Msolar (M-dwarf binary system), lens distance DL~5.5 kpc, and binary period P~1.5 yr. The robustness of our model is demonstrated by its striking agreement with MACHO/GMAN data that cover several sharp features in the light curve not probed by the PLANET observations, and which did not enter our modeling procedure in any way. Available data sets thus indicate that the light curve of MACHO 97-BLG-41 can be modeled as a source crossing two caustics of a physically realistic rotating binary. Thus, contrary to a recent suggestion, the additional effects of a postulated planetary companion to the binary lens are not required. Based on observations at Canopus Observatory, Tasmania, Australia; Perth Observatory, Bickley, Australia; the South African Astronomical Observatory, Sutherland, South Africa; the European Southern Observatory, La Silla, Chile; and the Cerro Tololo Inter-American Observatory, Cerro Tololo, Chile. ]]> http://telbib.eso.org/detail.php?id=19321 http://telbib.eso.org/detail.php?id=47974 Instruments: VIMOS
ProgramIDs: 175.A-0839
BibCode: 2013ApJ...768...51K

We investigated the fraction of [O II] emitters in galaxies at z ~ 0.9 as a function of the local galaxy density in the Hubble Space Telescope (HST) COSMOS 2 deg2 field. [O II] emitters are selected by the narrowband excess technique with the NB711-band imaging data taken with Suprime-Cam on the Subaru telescope. We carefully selected 614 photo-z-selected galaxies with M U3500 < –19.31 at z = 0.901 - 0.920, which includes 195 [O II] emitters, to directly compare the results with our previous study at z ~ 1.2. We found that the fraction is almost constant at 0.3 Mpc–2 < Σ10th < 10 Mpc–2. We also checked the fraction of galaxies with blue rest-frame colors of NUV – R < 2 in our photo-z-selected sample, and found that the fraction of blue galaxies does not significantly depend on the local density. On the other hand, the semi-analytic model of galaxy formation predicted that the fraction of star-forming galaxies at z ~ 0.9 decreases with increasing projected galaxy density even if the effects of the projection and the photo-z error in our analysis were taken into account. The fraction of [O II] emitters decreases from ~60% at z ~ 1.2 to ~30% at z ~ 0.9 independent of galaxy environment. The decrease of the [O II] emitter fraction could be explained mainly by the rapid decrease of star formation activity in the universe from z ~ 1.2 to z ~ 0.9. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA Inc, under NASA contract NAS 5-26555. Also based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under NASA contract 1407. Also based on data collected at the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan; the XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA; the European Southern Observatory under Large Program 175.A-0839, Chile; Kitt Peak National Observatory, Cerro Tololo Inter-American Observatory and the National Optical Astronomy Observatory, which are operated by the Association of Universities for Research in Astronomy, Inc. (AURA) under cooperative agreement with the National Science Foundation; and the Canada-France-Hawaii Telescope with MegaPrime/MegaCam operated as a joint project by the CFHT Corporation, CEA/DAPNIA, the NRC and CADC of Canada, the CNRS of France, TERAPIX, and the University of Hawaii. ]]> http://telbib.eso.org/detail.php?id=47974 http://telbib.eso.org/detail.php?id=47971 Instruments: FLAMES-GIRAFFE, X-SHOOTER
ProgramIDs: 083.B-0470, 60.A-9433
BibCode: 2013A&A...552A..95S

Context. The Lyman alpha emission line of neutral hydrogen is an important tool for finding galaxies at high redshift, thus for probing the structure of the early universe. However, the resonance nature of the line and its sensitivity to dust and neutral gas is still not fully understood. Aims: We present measurements of the velocity, covering fraction and optical depth of neutral gas in front of two well-known, local blue compact galaxies that show Lyman alpha in emission: ESO 338-IG 04 and Haro 11. We thus observationally test the hypothesis that Lyman alpha can escape through neutral gas by being Doppler shifted out of resonance. Methods: We present integral field spectroscopy, obtained with the GIRAFFE/Argus spectrograph at VLT/FLAMES in Paranal, Chile. The excellent wavelength resolution allowed us to accurately measure the velocity of the ionized and neutral gas through the Hα emission and Na D absorption, which trace the ionized medium and cold interstellar gas, respectively. We also present independent measurements from the VLT/X-shooter spectrograph that confirm our results. Results: For ESO 338-IG04 we measure no significant shift of neutral gas: the best fit velocity offset is - 15 ± 16 km s-1. For Haro 11, we see an outflow from knot B at 44 ± 13 km s-1, and infalling gas towards knot C with 32 ± 12 km s-1. Based on the relative strength of the Na D absorption lines, we estimate low covering fractions of neutral gas (down to 10%) in all three cases. Conclusions: The Na D absorption most likely occurs in dense clumps with higher column densities than the medium in which the bulk of the Ly α scattering takes place. Still, we find no strong correlation between outflowing neutral gas and strong Ly α emission. The Ly α photons from these two galaxies are therefore likely to be escaping due to a low column density and/or covering fraction. Based on observations made with ESO Telescopes at the Paranal Observatory under program IDs 083.B-0470 and 60.A-9433. ]]> http://telbib.eso.org/detail.php?id=47971 http://telbib.eso.org/detail.php?id=47970 Instruments: VISIR
ProgramIDs: 386.C-0111, 087.C-0833
BibCode: 2013A&A...552A..88G

Aims: We present mid-infrared observations and photometry of the circumstellar disks around PDS 66 and CRBR 2422.8-3423, obtained with VISIR/VLT in the N band and for the latter also in the Q band. Our aim is to resolve the inner regions of these protoplanetary disks, which carry potential signatures of intermediate or later stages of disk evolution and ongoing planet formation. Methods: We determined the radial brightness profiles of our target objects and the corresponding PSF reference that were observed before and after our target objects. Background standard deviations, the standard errors, and the seeing variations during the observations were considered. Adopting a simple radiative transfer model based on parameters taken from previous studies, we derived constraints on the inner-disk hole radius of the dust disk. Results: Neither of the circumstellar disks around our science targets are spatially resolved in our observations. However, we are able to constrain the inner-disk hole radius to <15.0-0.5+0.5 AU and <10.5-1.0+0.5 AU for PDS 66 and CRBR 2422.8-3423, respectively. The photometry we performed yields N-band flux densities of 599 ± 8 mJy for PDS 66 and 130 ± 14 mJy for CRBR 2422.8-3423, as well as a Q-band flux density of 858 ± 109 mJy for CRBR 2422.8-3423. ]]> http://telbib.eso.org/detail.php?id=47970 http://telbib.eso.org/detail.php?id=47967 Instruments: FLAMES-UV, FORS2
ProgramIDs: 072.B-0497, 171.B-0520
BibCode: 2013ApJ...767..131L

Building on our previous spectroscopic and photometric analysis of the isolated Local Group dwarf irregular (dIrr) galaxy WLM, we present a comparison of the metallicities of its red giant branch stars with respect to the well-studied Local Group dwarf spheroidal galaxies (dSphs) and Magellanic Clouds. We calculate a mean metallicity of [Fe/H] =–1.28 ± 0.02 and an intrinsic spread in metallicity of σ = 0.38 ± 0.04 dex, similar to the mean and spread observed in the massive dSph Fornax and the Small Magellanic Cloud. Thus, despite WLM's isolated environment, its global metallicity still follows expectations for mass and its global chemical evolution is similar to other nearby luminous dwarf galaxies (gas-rich or gas-poor). The data also show a radial gradient in [Fe/H] of d[Fe/H]/drc = –0.04 ± 0.04 dex {r_{c}^{-1}}, which is flatter than that seen in the unbiased and spatially extended surveys of dSphs. Comparison of the spatial distribution of [Fe/H] in WLM, the Magellanic Clouds, and a sample of Local Group dSphs shows an apparent dichotomy in the sense that the dIrrs have statistically flatter radial [Fe/H] gradients than the low angular momentum dSphs. The correlation between angular momentum and radial metallicity gradient is further supported when considering the Local Group dEs. This chemodynamic relationship offers a new and useful constraint for environment-driven dwarf galaxy evolution models in the Local Group. ]]> http://telbib.eso.org/detail.php?id=47967 http://telbib.eso.org/detail.php?id=47964 Instruments:
ProgramIDs:
BibCode: 2013ApJ...767..120M

Multi-band Hubble Space Telescope photometry reveals that the main sequence, sub-giant, and the red-giant branch of the globular cluster NGC 6752 splits into three main components in close analogy with the three distinct segments along its horizontal branch stars. These triple sequences are consistent with three stellar groups: a stellar population with a chemical composition similar to field-halo stars (Population a), a Population (c) with enhanced sodium and nitrogen, depleted carbon and oxygen, and an enhanced helium abundance (ΔY ~ 0.03), and a Population (b) with an intermediate (between Populations a and c) chemical composition and slightly enhanced helium (ΔY ~ 0.01). These components contain ~25% (Population a), ~45% (Population b), and ~30% (Population c) of the stars. No radial gradient for the relative numbers of the three populations has been identified out to about 2.5 half-mass radii. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555. ]]> http://telbib.eso.org/detail.php?id=47964 http://telbib.eso.org/detail.php?id=47963 Instruments: FORS1
ProgramIDs: 075.B-0298
BibCode: 2013ApJ...767..117O

We investigate the narrow-line region (NLR) of two radio-quiet QSOs, PG1012+008 and PG1307+085, using high signal-to-noise spatially resolved long-slit spectra obtained with FORS1 at the Very Large Telescope. Although the emission is dominated by the point-spread function of the nuclear source, we are able to detect extended NLR emission out to several kiloparsec scales in both QSOs by subtracting the scaled central spectrum from outer spectra. In contrast to the nuclear spectrum, which shows a prominent blue wing and a broad line profile of the [O III] line, the extended emission reveals no clear signs of large-scale outflows. Exploiting the wide wavelength range, we determine the radial change of the gas properties in the NLR, i.e., gas temperature, density, and ionization parameter, and compare them with those of Seyfert galaxies and type-II QSOs. The QSOs have higher nuclear temperature and lower electron density than Seyferts, but show no significant difference compared to type-II QSOs, while the ionization parameter decreases with radial distance, similar to the case of Seyfert galaxies, For PG1012+008, we determine the stellar-velocity dispersion of the host galaxy. Combined with the black hole mass, we find that the luminous radio-quiet QSO follows the local M BH-σ* relation of active galactic nuclei. ]]> http://telbib.eso.org/detail.php?id=47963 http://telbib.eso.org/detail.php?id=47961 Instruments: CRIRES
ProgramIDs: 086.C-0378, 084.C-0634
BibCode: 2013ApJ...767..112I

We analyze the accretion properties of 21 low-mass T Tauri stars using a data set of contemporaneous near-UV (NUV) through optical observations obtained with the Hubble Space Telescope Imaging Spectrograph and the ground-based Small and Medium Aperture Research Telescope System, a unique data set because of the nearly simultaneous broad wavelength coverage. Our data set includes accreting T Tauri stars in Taurus, Chamaeleon I, η Chamaeleon, and the TW Hydra Association. For each source we calculate the accretion rate (\dot{M}) by fitting the NUV and optical excesses above the photosphere, produced in the accretion shock, introducing multiple accretion components characterized by a range in energy flux (or density) for the first time. This treatment is motivated by models of the magnetospheric geometry and accretion footprints, which predict that high-density, low filling factor accretion spots coexist with low-density, high filling factor spots. By fitting the UV and optical spectra with multiple accretion components, we can explain excesses which have been observed in the near-IR. Comparing our estimates of \dot{M} to previous estimates, we find some discrepancies; however, they may be accounted for when considering assumptions for the amount of extinction and variability in optical spectra. Therefore, we confirm many previous estimates of the accretion rate. Finally, we measure emission line luminosities from the same spectra used for the \dot{M} estimates, to produce correlations between accretion indicators (Hβ, Ca II K, C II], and Mg II) and accretion properties obtained simultaneously. ]]> http://telbib.eso.org/detail.php?id=47961 http://telbib.eso.org/detail.php?id=47960 Instruments: SINFONI
ProgramIDs: 076.A-0527, 079.A-0341, 080.A-0330, 080.A-0339, 080.A-0635, 183.A-0781
BibCode: 2013ApJ...767..104N

We analyze the spectra, spatial distributions, and kinematics of Hα, [N II], and [S II] emission in a sample of 38, z ~ 2.2 UV/optically selected star-forming galaxies (SFGs) from the SINS and zC-SINF surveys, 34 of which were observed in the adaptive optics mode of SINFONI and 30 of those contain data presented for the first time here. This is supplemented by kinematic data from 43 z ~ 1-2.5 galaxies from the literature. None of these 81 galaxies is an obvious major merger. We find that the kinematic classification of high-z SFGs as "dispersion dominated" or "rotation dominated" correlates most strongly with their intrinsic sizes. Smaller galaxies are more likely "dispersion-dominated" for two main reasons: (1) the rotation velocity scales linearly with galaxy size but intrinsic velocity dispersion does not depend on size or may even increase in smaller galaxies, and as such, their ratio is systematically lower for smaller galaxies, and (2) beam smearing strongly decreases large-scale velocity gradients and increases observed dispersion much more for galaxies with sizes at or below the resolution. Dispersion-dominated SFGs may thus have intrinsic properties similar to "rotation-dominated" SFGs, but are primarily more compact, lower mass, less metal enriched, and may have higher gas fractions, plausibly because they represent an earlier evolutionary state. Based on observations at the Very Large Telescope (VLT) of the European Southern Observatory (ESO), Paranal, Chile (ESO program IDs 076.A-0527, 079.A-0341, 080.A-0330, 080.A-0339, 080.A-0635, and 183.A-0781). ]]> http://telbib.eso.org/detail.php?id=47960 http://telbib.eso.org/detail.php?id=47954 Instruments: EFOSC2_NTT
ProgramIDs: 60.A-9700
BibCode: 2013ApJ...767L..29O

IC 3418 is a dwarf irregular galaxy falling into the Virgo cluster, and a 17 kpc long trail is seen behind the galaxy, which is considered to have formed due to ram pressure stripping. The trail contains compact knots and diffuse blobs of ultraviolet and blue optical emission and, thus, it is a clear site of recent star formation but in an unusual environment, surrounded by a million degree intra-cluster medium. We report on our optical spectroscopy of a compact source in the trail, SDSS J122952.66+112227.8, and show that the optical spectrum is dominated by emission from a massive blue supergiant star. If confirmed, our report would mark the farthest star with spectroscopic observation. We interpret that a massive O-type star formed in situ in the trail has evolved recently out of the main sequence into this blue supergiant phase, and now lacks any detectable spectral sign of its associated H II region. We argue that turbulence within the ram pressure striped gaseous trail may play a dominant role for the star formation within such trails. ]]> http://telbib.eso.org/detail.php?id=47954 http://telbib.eso.org/detail.php?id=47935 Instruments: EFOSC2_NTT, HARPS, HAWK-I
ProgramIDs: 083.C-0377, 282.C-5019, 084.C-0185, 084.D-0056
BibCode: 2013MNRAS.430.3422A

We report detection of thermal emission from the exoplanet WASP-19b at 3.6, 4.5, 5.8 and 8.0 μm. We used the InfraRed Array Camera on the Spitzer Space Telescope to observe two occultations of WASP-19b by its host star. We combine our new detections with previous measurements of WASP-19b's emission at 1.6 and 2.09 μm to construct a spectral energy distribution of the planet's dayside atmosphere. By comparing this with model-atmosphere spectra, we find that the dayside atmosphere of WASP-19b lacks a strong temperature inversion. As WASP-19 is an active star (log R'HK = -4.50 ± 0.03), this finding supports the hypothesis of Knutson, Howard and Isaacson that inversions are suppressed in hot Jupiters orbiting active stars. The available data are unable to differentiate between a carbon-rich and an oxygen-rich atmosphere. ]]> http://telbib.eso.org/detail.php?id=47935 http://telbib.eso.org/detail.php?id=47936 Instruments: FEROS2.2
ProgramIDs: 084.B-0029
BibCode: 2013A&A...552A..63B

Context. To add to the growing collection of well-studied double periodic variables (DPVs) we have carried out the first spectroscopic and photometric analysis of the eclipsing binary DQ Velorum to obtain its main physical stellar and orbital parameters. Aims: Combining spectroscopic and photometric observations that cover several orbital cycles allows us to estimate the stellar properties of the binary components and the orbital parameters. We also searched for circumstellar material around the more massive star. Methods: We separated DQ Velorum composite spectra and measured radial velocities with an iterative method for double spectroscopic binaries. We obtained the radial velocity curves and calculated the spectroscopic mass ratio. We compared our single-lined spectra with a grid of synthetic spectra and estimated the temperature of the stars. We modeled the V-band light curve with a fitting method based on the simplex algorithm, which includes an accretion disc. To constrain the main stellar parameters we fixed the mass ratio and donor temperature to the values obtained by our spectroscopic analysis. Results: We obtain a spectroscopic mass ratio q = 0.31 ± 0.03 together with donor and gainer masses Md = 2.2 ± 0.2 M&sun;, Mg = 7.3 ± 0.3 M&sun;, the radii Rd = 8.4 ± 0.2 R&sun;, Rg = 3.6 ± 0.2 R&sun; and temperatures Td = 9400 ± 100 K, Tg = 18 500 ± 500 K for the stellar components. We find that DQ Vel is a semi-detached system consisting of a B3V gainer and an A1III donor star plus an extended accretion disc around the gainer. The disc is filling 89% of the gainer Roche lobe with a temperature of 6580 ± 300 K at the outer radius. It has a concave shape that is thicker at its edge (de = 0.6 ± 0.1 R&sun;) than at its centre (dc = 0.3 ± 0.1 R&sun;). We find a significant sub-orbital frequency of 0.19 d-1 in the residuals of the V-band light curve, which we interpret as a pulsation of an slowly pulsating B-type (SPB) of a gainer star. We also estimate the distance to the binary (d ~ 3.1 kpc) using the absolute radii, apparent magnitudes, and effective temperatures of the components found in our study. Table 1 is available in electronic form at http://www.aanda.org ]]> http://telbib.eso.org/detail.php?id=47936 http://telbib.eso.org/detail.php?id=47951 Instruments: VIMOS, WFI
ProgramIDs: 168.A-0485
BibCode: 2013MNRAS.431L..68R

In this third paper in a series on the nature of extended, asymmetric Lyα emitters at z ˜ 3 we report the discovery, in an ultra-deep, blind, spectroscopic long-slit survey, of a Lyα emitting halo around a QSO at redshift 3.045. The QSO is a previously known, obscured active galactic nucleus (AGN). The Lyα emitting halo appears extended along the direction of the slit and exhibits two faint patches separated by 17 proper kpc in projection from the QSO. Comparison of the two-dimensional spectrum with archival Hubble Space Telescope ACS images shows that these patches coincide spatially with emission from a peculiar, dumbbell-shaped, faint galaxy. The assumptions that the Lyα emission patches are originating in the galaxy and that the galaxy is physically related to the QSO are at variance with photometric estimates of the galaxy redshift. We show, however, that a population of very young stars at the redshift of the QSO may fit the existing rest-frame broad-band UV photometry of the galaxy. If this scenario is correct, then the symmetry of the galaxy in continuum and Lyα emission, the extension of the QSO's Lyα emission in its direction, and the likely presence of a young stellar population in close proximity to a (short-lived) AGN suggest that this may be an example of AGN feedback triggering external star formation in high-redshift galaxies. ]]> http://telbib.eso.org/detail.php?id=47951 http://telbib.eso.org/detail.php?id=47949 Instruments: UVES
ProgramIDs: 266.D-5655
BibCode: 2013MNRAS.431L..10R

We present phase-resolved spectroscopy and photometry of the optical counterpart to the X-ray binary IGR J19308+0530. Ellipsoidal modulations in the light curve show that the F-type companion star in the system is Roche lobe filling. The optical spectra are dominated by absorption features from the donor star, with ˜10-20 per cent disc contribution to the optical continuum. We measure an orbital period of 14.662 ± 0.001 h, a radial velocity semi-amplitude for the companion star of K2 = 91.4 ± 1.4 km s- 1 and a rotational broadening of v sin i = 108.9 ± 0.6 km s- 1. From K2 and v sin i, given that the donor star is filling its Roche lobe, we derive a mass ratio of q = M2/M1 = 1.78 ± 0.04, which is typically considered to be too large for stable Roche lobe overflow. Our observations support an inclination of ˜50°. The accretor in IGR J19308+0530 is most likely a white dwarf, although a neutron star cannot entirely be excluded. ]]> http://telbib.eso.org/detail.php?id=47949 http://telbib.eso.org/detail.php?id=47946 Instruments: UVES
ProgramIDs: 284.D-5048
BibCode: 2013MNRAS.431..159K

Among the distinguishing characteristics of the remarkable hot R Coronae Borealis star DY Centauri, which was recently found to be a spectroscopic binary, is the presence of nebular forbidden lines in its optical spectrum. A compilation of photometry from 1970 to the present suggests that the star has evolved to higher effective temperatures. A comparison of spectra from 2010 with earlier spectra has shown that between 2003 and 2010, the 6717 and 6730 Å emission lines of [S II] underwent a dramatic change in their fluxes. This suggests that there was an increase in the nebula's electron density from 290 to 3140 cm-3 between 1989 and 2010, while the stellar temperature increased from 19 500 to 25 000 K. The nebular radius is about 0.02 pc, which is 60 000 times larger than the semimajor axis of the DY Cen binary system. The rapid changes of stellar temperature and the nebula's response to these changes demonstrate stellar evolution in action. ]]> http://telbib.eso.org/detail.php?id=47946 http://telbib.eso.org/detail.php?id=47942 Instruments: UVES
ProgramIDs: 65.O-0296, 60.A-9022, 166.A-0106
BibCode: 2013A&A...552A..77K

We have investigated the distribution and evolution of ~3100 intergalactic neutral hydrogen (H i) absorbers with H I column densities log NH I = [12.75,17.0] at 1.9 < z < 3.2, using 18 high resolution, high signal-to-noise quasar spectra obtained from the ESO VLT/UVES archive. We used two sets of Voigt profile fitting analysis, one including all the available high-order Lyman lines to obtain reliable H I column densities of saturated lines, and another using only the Lyα transition. There is no significant difference between the Lyα-only fit and the high-order Lyman fit results. Combining our Lyα-only fit results at 1.7 < z < 3.6 with high-quality literature data, the mean number density at 0 < z < 4 is not well described by a single power law and strongly suggests that its evolution slows down at z ≤ 1.5 at the high and low column density ranges. We also divided our entire H I absorbers at 1.9 < z < 3.2 into two samples, the unenriched forest and the C IV-enriched forest, depending on whether H I lines are associated with C IV at log NC IV ≥ 12.2 within a given velocity range. The entire H I column density distribution function (CDDF) can be described as the combination of these two well-characterised populations which overlap at log NH I ~ 15. At log NH I ≤ 15, the unenriched forest dominates, showing a similar power-law distribution to the entire forest. The C IV-enriched forest dominates at log NH I ≥ 15, with its distribution function as ∝NH I~-1.45. However, it starts to flatten out at lower NH I, since the enriched forest fraction decreases with decreasing NH I. The deviation from the power law at log NH I = [14,17] shown in the CDDF for the entire H I sample is a result of combining two different H I populations with a different CDDF shape. The total H I mass density relative to the critical density is ΩH I ~ 1.6 × 10-6 h-1, where the enriched forest accounts for ~40% of ΩH I. The data used in this study are taken from the ESO archive for the UVES at the VLT, ESO, Paranal, Chile.Appendix A is available in electronic form at http://www.aanda.org ]]> http://telbib.eso.org/detail.php?id=47942 http://telbib.eso.org/detail.php?id=47939 Instruments: VIRCAM
ProgramIDs: 179.B-2002
BibCode: 2013A&A...552A..74W

Context. Planetary nebulae (PNe) are powerful tracers of evolved stellar populations. Among the 3000 known PNe in the Galaxy, about 600 are located within the 520 square-degree area covered by the VVV survey. The VVV photometric catalogue provides an important new dataset for the study of PNe, with high-resolution imaging in five near-infrared bands. Aims: There are various colour-colour diagrams that can be obtained from the VVV filters. We investigate the location of PNe in these diagrams and the separation from other types of objects. This includes the new Y-J vs. Z-Y diagram. Methods: Aperture photometry of known PNe in the VVV area was retrieved from source catalogues. Care was taken to minimise any confusion with field stars. The colours of the PNe we are determined for (H-Ks), (J-H), (Z-Y), and (Y-J), and compared to stars and to other types of emission line objects. Cloudy photo-ionisation models were used to predict colours for typical PNe. Results: We present near-infrared photometry for 353 known PNe. The best separation from other objects is obtained in the (H-Ks) vs. (J-H) diagram. We calculated the emission-line contribution to the in-band flux based on a model for NGC 6720: we find that this is highest in the Z and Y bands at over 50%, lower in the J band at 40%, and lowest in the H and Ks bands at 20%. A new view of PNe in the wavelength domain of the Z and Y bands is shown. Photo-ionisation models are used to explore the observed colours in these bands. The Y band is shown to be dominated by He I 1.083 μm and He II 1.012 μm, and colours involving this band are very sensitive to the temperature of the ionizing star. Conclusions: The VVV survey represents a unique dataset for studying crowded and obscured regions in the Galactic plane. The diagnostic diagrams presented here allow one to study the properties of known PNe and to uncover objects not previously classified. Tables 3-5 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/552/A74 ]]> http://telbib.eso.org/detail.php?id=47939 http://telbib.eso.org/detail.php?id=47937 Instruments: FORS2
ProgramIDs: 085.A-0613
BibCode: 2013ApJ...767...39M

We present a new two-color algorithm, the "Stellar Bump Sequence" (SBS), that is optimized for robustly identifying candidate high-redshift galaxy clusters in combined wide-field optical and mid-infrared (MIR) data. The SBS algorithm is a fusion of the well-tested cluster red-sequence method of Gladders & Yee with the MIR 3.6 μm-4.5 μm cluster detection method developed by Papovich. As with the cluster red-sequence method, the SBS identifies candidate overdensities within 3.6 μm-4.5 μm color slices, which are the equivalent of a rest-frame 1.6 μm stellar bump "red-sequence." In addition to employing the MIR colors of galaxies, the SBS algorithm incorporates an optical/MIR (z'-3.6 μm) color cut. This cut effectively eliminates foreground 0.2 <z < 0.4 galaxies which have 3.6 μm-4.5 μm colors that are similarly red as z > 1.0 galaxies and add noise when searching for high-redshift galaxy overdensities. We demonstrate using the z ~ 1 GCLASS cluster sample that similar to the red sequence, the stellar bump sequence appears to be a ubiquitous feature of high-redshift clusters, and that within that sample the color of the stellar bump sequence increases monotonically with redshift and provides photometric redshifts accurate to Δz = 0.05. We apply the SBS method in the XMM-LSS SWIRE field and show that it robustly recovers the majority of confirmed optical, MIR, and X-ray-selected clusters at z > 1.0 in that field. Lastly, we present confirmation of SpARCS J022427-032354 at z = 1.63, a new cluster detected with the method and confirmed with 12 high-confidence spectroscopic redshifts obtained using FORS2 on the Very Large Telescope. We conclude with a discussion of future prospects for using the algorithm. ]]> http://telbib.eso.org/detail.php?id=47937 http://telbib.eso.org/detail.php?id=47898 Instruments: SINFONI
ProgramIDs: 077.B-0553
BibCode: 2013MNRAS.431.2294R

We present the first near-IR integral field spectroscopy observations of the galaxy MCG-6-30-15. The H-band data studied in this paper cover the central 500 pc of the galaxy at the best resolution (0.1 arcsec) so far. The spectra of the innermost regions are dominated by broad Brackett series emission lines and non-stellar continuum, under which we are able to trace the distribution and kinematics of the stars and also the [Fe II] line emission. We find that there is a counter-rotating stellar core extending out to 125 pc, which appears to be associated with the [Fe II] emission. Based on the mass-to-light ratio, and the presence of this emission line, we estimate the age of the central stellar population to be of the order of 65 Myr. We show that the gas needed to fuel the black hole is, at most, only 1 per cent of that needed to form these stars. We derive independent constraints on the black hole mass using the dynamical information and determine an upper limit for the black hole mass, MBH < 6 × 107 M&sun;, that is consistent with other estimates. ]]> http://telbib.eso.org/detail.php?id=47898 http://telbib.eso.org/detail.php?id=47933 Instruments: LABOCA, SABOCA
ProgramIDs: 086.C-0848, 088.C-0994, 090.C-0894, 284.C-5015
BibCode: 2013ApJ...767...36S

We perform a census of the reddest, and potentially youngest, protostars in the Orion molecular clouds using data obtained with the PACS instrument on board the Herschel Space Observatory and the LABOCA and SABOCA instruments on APEX as part of the Herschel Orion Protostar Survey (HOPS). A total of 55 new protostar candidates are detected at 70 μm and 160 μm that are either too faint (m 24 > 7 mag) to be reliably classified as protostars or undetected in the Spitzer/MIPS 24 μm band. We find that the 11 reddest protostar candidates with log λF λ70/λF λ24 > 1.65 are free of contamination and can thus be reliably explained as protostars. The remaining 44 sources have less extreme 70/24 colors, fainter 70 μm fluxes, and higher levels of contamination. Taking the previously known sample of Spitzer protostars and the new sample together, we find 18 sources that have log λF λ70/λF λ24 > 1.65; we name these sources "PACS Bright Red sources," or PBRs. Our analysis reveals that the PBR sample is composed of Class 0 like sources characterized by very red spectral energy distributions (SEDs; T bol < 45 K) and large values of sub-millimeter fluxes (L smm/L bol > 0.6%). Modified blackbody fits to the SEDs provide lower limits to the envelope masses of 0.2-2 M &sun; and luminosities of 0.7-10 L &sun;. Based on these properties, and a comparison of the SEDs with radiative transfer models of protostars, we conclude that the PBRs are most likely extreme Class 0 objects distinguished by higher than typical envelope densities and hence, high mass infall rates. ]]> http://telbib.eso.org/detail.php?id=47933 http://telbib.eso.org/detail.php?id=47931 Instruments: HARPS
ProgramIDs: 60.A-9036, 072.C-0488, 077.C-0364, 082.C-0718, 085.C-0019, 087.C-0831, 180.C-0886, 183.C-0437
BibCode: 2013ApJ...767...28P

We construct high signal-to-noise "template" spectra by co-adding hundreds of spectra of nearby dwarfs spanning K7 to M4, taken with Keck/HIRES as part of the California Planet Search. We identify several spectral regions in the visible (370-800 nm) that are sensitive to the stellar luminosity and metallicity. We use these regions to develop a spectral calibration method to measure the mass, metallicity, and distance of low-mass stars, without the requirement of geometric parallaxes. Testing our method on a sample of nearby M dwarfs, we show that we can reproduce stellar masses to about 8%-10%, metallicity to ~0.15 dex, and distance to 11%. We were able to make use of HIRES spectra obtained as part of the radial velocity monitoring of the star KOI-314 to derive a new mass estimate of 0.57 ± 0.05 M &#9737;, a radius of 0.54 ± 0.05 R &#9737;, a metallicity, [Fe/H], of –0.28 ± 0.10, and a distance of 66.5 ± 7.3 pc. Using HARPS archival data and combining our spectral method with constraints from transit observations, we are also able to derive the stellar properties of GJ 3470, a transiting planet hosting M dwarf. We estimate a mass of 0.53 ± 0.05 M &#9737;, a radius of 0.50 ± 0.05 R &#9737;, a metallicity, [Fe/H], of 0.12 ± 0.12, and a distance of 29.9+/- _{3.4}^{3.7} pc. ]]> http://telbib.eso.org/detail.php?id=47931 http://telbib.eso.org/detail.php?id=47924 Instruments: FORS1
ProgramIDs: 078.B-0310
BibCode: 2013ApJ...767...13S

We present results from a study to determine whether relations—established in the local universe—between the mass of supermassive black holes (SMBHs) and their host galaxies are in place at higher redshifts. We identify a well-constructed sample of 18 X-ray-selected, broad-line active galactic nuclei (AGNs) in the Extended Chandra Deep Field-South Survey with 0.5 < z < 1.2. This redshift range is chosen to ensure that Hubble Space Telescope (HST) imaging is available with at least two filters that bracket the 4000 Å break, thus providing reliable stellar mass estimates of the host galaxy by accounting for both young and old stellar populations. We compute single-epoch, virial black hole (BH) masses from optical spectra using the broad Mg II emission line. For essentially all galaxies in our sample, their total stellar mass content agrees remarkably well, given their BH masses, with local relations of inactive galaxies and active SMBHs. We further decompose the total stellar mass into bulge and disk components separately with full knowledge of the HST point-spread function. We find that ~80% of the sample is consistent with the local M BH-M *, Bulge relation even with 72% of the host galaxies showing the presence of a disk. In particular, bulge-dominated hosts are more aligned with the local relation than those with prominent disks. We further discuss the possible physical mechanisms that are capable of building up the stellar mass of the bulge from an extended disk of stars over the subsequent 8 Gyr. ]]> http://telbib.eso.org/detail.php?id=47924 http://telbib.eso.org/detail.php?id=47926 Instruments: FEROS2.2
ProgramIDs: 087.A-9013
BibCode: 2013MNRAS.430.2018S

We present the analysis of photometric and spectroscopic data of six bright Galactic Cepheids: GH Carinae, V419 Centauri, V898 Centauri, AD Puppis, AY Sagittarii and ST Velorum. Based on new radial velocity data (in some cases supplemented with earlier data available in the literature), these Cepheids have been found to be members in spectroscopic binary systems. V898 Cen turned out to have one of the largest orbital radial velocity amplitude (>40 km s-1) among the known binary Cepheids. The data are insufficient to determine the orbital periods nor other orbital elements for these new spectroscopic binaries. These discoveries corroborate the statement on the high frequency of occurrence of binaries among the classical Cepheids, a fact to be taken into account when calibrating the period-luminosity relationship for Cepheids. We have also compiled all available photometric data that revealed that the pulsation period of AD Pup, the longest period Cepheid in this sample, is continuously increasing with ΔP = 0.004567d century-1, likely to be caused by stellar evolution. The wave-like pattern superimposed on the parabolic O - C graph of AD Pup may well be caused by the light-time effect in the binary system. ST Vel also pulsates with a continuously increasing period. The other four Cepheids are characterized with stable pulsation periods in the last half century. ]]> http://telbib.eso.org/detail.php?id=47926 http://telbib.eso.org/detail.php?id=47917 Instruments: LABOCA, SHFI
ProgramIDs: 081.F-9405, 082.B-0852
BibCode: 2013A&A...552L...4M

We report the discovery with the Atacama Pathfinder EXperiment (APEX) of an outflow of molecular gas in the radio-loud Seyfert galaxy IC 5063 (z = 0.0110). In addition to the emission of the large-scale CO disk, a prominent blueshifted wing is observed in the CO(2-1) spectrum. IC 5063 represents one of the best cases of a fast jet-driven H I (and ionized gas) outflow, which is located at the site of a radio-bright feature about 0.5 kpc from the nucleus. It is possible that the blueshifted part of the molecular gas is associated with this outflow and is accelerated by the interaction with the radio jet. The outflow of molecular gas is characterized by an H2 mass of the outflowing component of between 2.25 ± 0.70 × 107M&sun; and 1.29 ± 0.40 × 108M&sun; and a mass outflow rate between 22 and 129 M&sun; yr-1 depending on the assumption for αX and assuming a luminosity ratio L'CO(2-1)/L'CO(1-0) = 1. This confirms that this may indeed be the dominant component in outflows driven by the nuclear activity as also found in other objects. However, this high mass outflow rate cannot easily be supported for a long time, suggesting that the gas outflow in IC 5063 happens in bursts and is in a particularly strong phase at present. Owing to its proximity, IC 5063 serves as an excellent laboratory for understanding the impact of radio jets on the gas-rich inter-stellar medium. ]]> http://telbib.eso.org/detail.php?id=47917 http://telbib.eso.org/detail.php?id=47910 Instruments: ISAAC
ProgramIDs: 65.H-0422, 69.D-0646, 67.D-0547
BibCode: 2013MNRAS.430.1832H

GRS 1915+105 has the largest mass function of any Galactic black hole system, although the error is relatively large. Here we present spectroscopic analysis of medium-resolution infrared Very Large Telescope archival data of GRS 1915+105 in the K band. We find an updated ephemeris, and report on attempts to improve the mass function by a refinement of the radial velocity estimate. We show that the spectra are significantly affected by the presence of phase-dependent CO bandhead emission, possibly originating from the accretion disc: we discuss the impact this has on efforts to better constrain the black hole mass. We report on a possible way to measure the radial velocity utilizing apparent H-band atomic absorption features and also discuss the general uncertainty of the system parameters of this well-studied object. ]]> http://telbib.eso.org/detail.php?id=47910 http://telbib.eso.org/detail.php?id=47905 Instruments: WFI
ProgramIDs: 088.A-9012
BibCode: 2013MNRAS.431.2126M

We present a general overview and the first results of the SUMO project (a SUrvey of Multiple pOpulations in Globular Clusters). The objective of this survey is the study of multiple stellar populations in the largest sample of globular clusters homogeneously analysed to date. To this aim we obtained high signal-to-noise (S/N > 50) photometry for main sequence stars with mass down to ˜0.5 M&sun; in a large sample of clusters using both archival and proprietary U, B, V and I data from ground-based telescopes. In this paper, we focus on the occurrence of multiple stellar populations in 23 clusters. We define a new photometric index, cU, B, I = (U - B) - (B - I), which turns out to be very effective for identifying multiple sequences along the red giant branch (RGB). We found that in the V-cU, B, I diagram all clusters presented in this paper show broadened or multimodal RGBs, with the presence of two or more components. We found a direct connection with the chemical properties of different sequences, which display different abundances of light elements (O, Na, C, N and Al). The cU, B, I index is also a powerful tool for identifying distinct sequences of stars along the horizontal branch and, for the first time in the case of NGC 104 (47 Tuc), along the asymptotic giant branch. Our results demonstrate that (i) the presence of more than two stellar populations is a common feature amongst globular clusters, as already highlighted in previous work; (ii) multiple sequences with different chemical contents can be easily identified by using standard Johnson photometry obtained with ground-based facilities; (iii) in the study of globular cluster multiple stellar populations the cU, B, I index is an alternative to spectroscopy, and has the advantage of larger statistics. ]]> http://telbib.eso.org/detail.php?id=47905 http://telbib.eso.org/detail.php?id=47904 Instruments: HARPS
ProgramIDs: 184.C-0639
BibCode: 2013A&A...553A..30T

We present the study of the CoRoT transiting planet candidate 101186644, also named LRc01_E1_4780. Analysis of the CoRoT lightcurve and the HARPS spectroscopic follow-up observations of this faint (mV = 16) candidate revealed an eclipsing binary composed of a late F-type primary (Teff = 6090 ± 200 K) and a low-mass, dense late M-dwarf secondary on an eccentric (e = 0.4) orbit with a period of ~20.7 days. The M-dwarf has a mass of 0.096 ± 0.011 M&sun;, and a radius of 0.104-0.006+0.026 R&sun;, which possibly makes it the smallest and densest late M-dwarf reported so far. Unlike the claim that theoretical models predict radii that are 5-15% smaller than measured for low-mass stars, this one seems to have a radius that is consistent and might even be below the radius predicted by theoretical models. Based on observations made with the 1-m telescope at the Wise Observatory, Israel, the Swiss 1.2-m Leonhard Euler telescope at La Silla Observatory, Chile, the IAC-80 telescope at the Observatory del Teide, Canarias, Spain, and the 3.6-m telescope at La Silla Observatory (ESO), Chile (program 184.C-0639). ]]> http://telbib.eso.org/detail.php?id=47904 http://telbib.eso.org/detail.php?id=47902 Instruments: EMMI
ProgramIDs: 080.D-0685
BibCode: 2013A&A...553A..18S

We report the discovery of a bright (mV = 11.6 mag), eclipsing, hot subdwarf binary of spectral type B with a late main sequence companion from the All Sky Automated Survey (ASAS 102322-3737.0). Such systems are called HW Vir stars after the prototype. The lightcurve shows a grazing eclipse and a strong reflection effect. An orbital period of P = 0.13927 d, an inclination of i = 65.86°, a mass ratio q = 0.34, a radial velocity semiamplitude K1 = 81.0 km s-1, and other parameters were derived from a combined spectroscopic and photometric analysis. The short period can only be explained by a common envelope origin of the system. The atmospheric parameters (Teff = 28 400 K, log g = 5.60) are consistent with a core helium-burning star located on the extreme horizontal branch. In agreement with that we derived the most likely sdB mass to be MsdB = 0.46 M&sun;, close to the canonical mass of such objects. The companion is a late M-dwarf with a mass of Mcomp = 0.16 M&sun;. ASAS 102322-3737.0 is the third brightest of only 12 known HW Virginis systems, which makes it an ideal target for detailed spectroscopic studies and long-term photometric monitoring to search for period variations, e.g., those caused by a substellar companion. ]]> http://telbib.eso.org/detail.php?id=47902 http://telbib.eso.org/detail.php?id=47899 Instruments: UVES
ProgramIDs: 085.D-0124
BibCode: 2013MNRAS.431.2808K

We have carried out a survey of short-period pulsations among a sample of carefully chosen cool Ap stars using time-resolved observations with the Ultraviolet and Visual Echelle Spectrograph at the European Southern Observatory ESO 8 m Very Large Telescope. Here, we report the discovery of pulsations with amplitudes 50-100 m s-1 and periods 7-12 min in HD 132205, HD 148593 and HD 151860. These objects are therefore established as new rapidly oscillating Ap (roAp) stars. In addition, we independently confirm the presence of pulsations in HD 69013, HD 96237 and HD 143487 and detect, for the first time, radial velocity oscillations in two previously known photometric roAp stars HD 119027 and HD 185256. At the same time, no pulsation variability is found for HD 5823, HD 178892 and HD 185204. All of the newly discovered roAp stars were previously classified as non-pulsating based on the low-precision ground-based photometric surveys. This shows that such observations cannot be used to reliably distinguish between pulsating and non-pulsating stars and that all cool Ap stars may harbour p-mode pulsations of different amplitudes. ]]> http://telbib.eso.org/detail.php?id=47899 http://telbib.eso.org/detail.php?id=47897 Instruments: X-SHOOTER
ProgramIDs: 085.D-0497
BibCode: 2013ApJ...768..185S

We present a new dynamical study of the black hole X-ray transient GRS1915+105 making use of near-infrared spectroscopy obtained with X-shooter at the Very Large Telescope. We detect a large number of donor star absorption features across a wide range of wavelengths spanning the H and K bands. Our 24 epochs covering a baseline of over 1 yr permit us to determine a new binary ephemeris including a refined orbital period of P = 33.85 ± 0.16 days. The donor star radial velocity curves deliver a significantly improved determination of the donor semi-amplitude which is both accurate (K 2 = 126 ± 1 km s–1) and robust against choice of donor star template and spectral features used. We furthermore constrain the donor star's rotational broadening to vsin i = 21 ± 4 km s–1, delivering a binary mass ratio of q = 0.042 ± 0.024. If we combine these new constraints with distance and inclination estimates derived from modeling the radio emission, a black hole mass of M BH = 10.1 ± 0.6 M &#9737; is inferred, paired with an evolved mass donor of M 2 = 0.47 ± 0.27 M &#9737;. Our analysis suggests a more typical black hole mass for GRS1915+105 rather than the unusually high values derived in the pioneering dynamical study by Greiner et al. Our data demonstrate that high-resolution infrared spectroscopy of obscured accreting binaries can deliver dynamical mass determinations with a precision on par with optical studies. ]]> http://telbib.eso.org/detail.php?id=47897 http://telbib.eso.org/detail.php?id=47896 Instruments: CRIRES, SOFI
ProgramIDs: 079.C-0717, 65.I-0576, 67.C-0284
BibCode: 2013A&A...553A..41Z

Context. Proper motion measurements provide unique and powerful means to identify the driving sources of mass outflows, which are of particular importance in regions with complex star formation activity and deeply embedded protostars. They also provide the necessary kinematic information to study the dynamics of mass outflows, the interaction between outflows and the ambient medium, and the evolution of outflows with the age of the driving sources. Aims: We aim to take a census of molecular hydrogen emission line objects (MHOs) in the ρ Ophiuchi molecular cloud and to make the first systematic proper motion measurements of these objects in this region. The driving sources are identified based on the measured proper motions, and the outflow properties are characterized. The relationship between outflow properties and the evolutionary stages of the driving sources are also investigated. Methods: Deep H2 near-infrared imaging is performed to search for molecular hydrogen emission line objects. Multi-epoch data are used to derive the proper motions of the features of these objects, and the lengths and opening angles of the molecular hydrogen outflows. Results: Our imaging covers an area of ~0.11 deg2 toward the L1688 core in the ρ Ophiuchi molecular cloud. In total, six new MHOs are discovered, 32 previously known MHOs are detected, and the proper motions for 86 features of the MHOs are measured. The proper motions lie in the range of 14 to 247 mas/yr, corresponding to transversal velocities of 8 to 140 km s-1 with a median velocity of about 35 km s-1. Based on morphology and proper motion measurements, 27 MHOs are ascribed to 21 driving sources. The molecular hydrogen outflows have a median length of ~0.04 pc and random orientations. We find no obvious correlation between H2 jet length, jet opening angle, and the evolutionary stage of the driving sources as defined by their spectral indices. We find that the fraction of protostars (23%) that drive molecular hydrogen outflows is similar to the one for Class II sources (15%). For most molecular hydrogen outflows, no obvious velocity variation along the outflow has been found. Conclusions: In Ophiuchus the frequency of occurrence of molecular hydrogen outflows has no strong dependency on the evolutionary stage of the driving source during the evolution from the protostellar stage to the classical T Tauri stage. Based on observations made with ESO New Technology Telescope at La Silla under programme ID 079.C- 0717(B), and on data obtained from the ESO Science Archive Facility.Appendix A is available in electronic form at http://www.aanda.org ]]> http://telbib.eso.org/detail.php?id=47896 http://telbib.eso.org/detail.php?id=47893 Instruments: FORS2, VIMOS
ProgramIDs: 70.A-0378, 075.A-0483, 077.A-0517, 088.A-0232
BibCode: 2013ApJ...768..104F

The RCS 2319+00 supercluster is a massive supercluster at z = 0.9 comprising three optically selected, spectroscopically confirmed clusters separated by <3 Mpc on the plane of the sky. This supercluster is one of a few known examples of the progenitors of present-day massive clusters (1015 M &#9737; by z ~ 0.5). We present an extensive spectroscopic campaign carried out on the supercluster field resulting, in conjunction with previously published data, in 1961 high-confidence galaxy redshifts. We find 302 structure members spanning three distinct redshift walls separated from one another by ~65 Mpc (Δ z = 0.03). The component clusters have spectroscopic redshifts of 0.901, 0.905, and 0.905. The velocity dispersions are consistent with those predicted from X-ray data, giving estimated cluster masses of ~1014.5-1014.9 M &#9737;. The Dressler-Shectman test finds evidence of substructure in the supercluster field and a friends-of-friends analysis identified five groups in the supercluster, including a filamentary structure stretching between two cluster cores previously identified in the infrared by Coppin et al. The galaxy colors further show this filamentary structure to be a unique region of activity within the supercluster, comprised mainly of blue galaxies compared to the ~43%-77% red-sequence galaxies present in the other groups and cluster cores. Richness estimates from stacked luminosity function fits result in average group mass estimates consistent with ~1013 M &#9737; halos. Currently, 22% of our confirmed members reside in >~ 1013 M &#9737; groups/clusters destined to merge onto the most massive cluster, in agreement with the massive halo galaxy fractions important in cluster galaxy pre-processing in N-body simulation merger tree studies. ]]> http://telbib.eso.org/detail.php?id=47893 http://telbib.eso.org/detail.php?id=47892 Instruments: SINFONI
ProgramIDs: 083.B-0332
BibCode: 2013ApJ...768..107H

In a matched sample of Seyfert and quiescent galaxies we simultaneously probe the stellar and molecular gas kinematics from 1 kpc down to 50 pc with the aim of identifying the dynamical processes dictating black hole accretion rates. This first paper compares the global characteristics of a sample of 10 galaxies. We find several differences within a radius of 500 pc that are correlated with active galactic nucleus (AGN) activity. The Seyferts have (1) a more centrally concentrated nuclear stellar surface brightness with lower stellar luminosities beyond a radius of 100 pc, (2) a lower stellar velocity dispersion within a radius of 200 pc, (3) elevated H2 1-0 S(1) luminosity out to a radius of at least 250 pc, and (4) more centrally concentrated H2 surface brightness profiles. These observed differences can be interpreted as evidence for Seyfert galaxies having a dynamically cold (in comparison to the bulge) nuclear structure composed of a significant gas reservoir and a relatively young stellar population. This structure is undetected (and possibly does not exist) in quiescent galaxies. The presence of such a nuclear structure in Seyfert galaxies provides evidence for inflow of the surrounding interstellar medium since the nuclear stellar population requires a supply of gas from which to form. The fueling of a Seyfert AGN is thus associated with the formation of a dynamically cold component of gas and stars on scales of hundreds of parsecs. Based on observations at the ESO Very Large Telescope (083.B-0332). ]]> http://telbib.eso.org/detail.php?id=47892 http://telbib.eso.org/detail.php?id=47868 Instruments: HARPS, UVES
ProgramIDs: 072.C-0488, 65.L-0428, 66.C-0446, 267.C-5700, 68.C-0415, 69.C-0722, 70.C-0044, 71.C-0498, 072.C-0495, 173.C-0606, 078.C-0829
BibCode: 2013A&A...553A...8D

Context. M dwarfs have often been found to have super-Earth planets with short orbital periods. These stars are thus preferential targets in searches for rocky or ocean planets in the solar neighborhood. Aims: Our research group recently announced the discovery of one and two low-mass planets around the M1.5V stars Gl 433 and Gl 667C, respectively. We found these planets with the HARPS spectrograph on the ESO 3.6-m telescope at La Silla Observatory, from observations obtained during the guaranteed time observing program of that instrument. Methods: We obtained additional HARPS observations of those two stars, for a total of 67 and 179 radial velocity measurements for Gl 433 and Gl 667C, respectively, and present here an orbital analysis of these extended data sets and our main conclusions about both planetary systems. Results: One of the three planets, Gl 667Cc, has a mass of only M2sini ~ 4.25 M⊕ and orbits in the central habitable zone of its host star. It receives only 10% less stellar energy from Gl 667C than the Earth receives from the Sun. However, planet evolution in the habitable zone can be very different if the host star is a M dwarf or a solar-like star, without necessarily questioning the presence of water. The two other planets, Gl 433b and Gl 667Cb, both have M2sini of ~5.5 M⊕ and periods of ~7 days. The radial velocity measurements of both stars contain longer timescale signals, which we fit with longer period Keplerians. For Gl 433, the signal probably originates in a magnetic cycle, while data of longer time span will be needed before conclusive results can be obtained for Gl 667C. The metallicity of Gl 433 is close to solar, while Gl 667C is metal poor with [Fe/H] ~ -0.6. This reinforces the recent conclusion that the occurrence of super-Earth planets does not strongly correlate with the stellar metallicity. Based on observations collected with HARPS instrument on the 3.6-m telescope at La Silla Observatory (European Southern Observatory) under programs ID072.C-0488(E).Appendix A is available in electronic form at http://www.aanda.org ]]> http://telbib.eso.org/detail.php?id=47868 http://telbib.eso.org/detail.php?id=47888 Instruments: SOFI
ProgramIDs: 077.C-0549
BibCode: 2013MNRAS.431.2230V

New photometric observations of the hierarchical eclipsing TY CrA system were taken in the optical with Variable Young Stellar Object Survey 6 (VYSOS6) and in the near-infrared (IR) with Son of ISAAC (SOFI) and Rapid Eye Mount Infra Red (REMIR). They are the first observations showing the deep eclipse minimum of the pre-main-sequence secondary in the near-IR. For the first time, the secondary minimum can be reliably used in the calculation of the O-C diagram of TY CrA. By now, the O-C diagram can be studied on a time basis of about two decades. We confirm, that the O-C diagram cannot be explained by the spectroscopic tertiary. For the first time, the light curve of the inner eclipsing binary is analysed in both optical and near-IR bands simultaneously. In combination with already published spectroscopic elements, precise absolute dimensions and masses of the primary and the secondary component are obtained using the ROCHE code. The inclusion of the near-IR data puts strong constraints on the third light which is composed of the reflection nebula, the spectroscopic tertiary and a visual fourth component. The absolute parameters of the inner eclipsing binary agree very well with previous work except of the primary radius (1.46 ± 0.15 R&sun;) and luminosity (40 ± 10 L&sun;) which are clearly smaller. While the parameters of the secondary are well understood when assuming an age of about 3-5 Myr, the primary seems considerably undersized. Low metallicity cannot explain the parameters of the primary. ]]> http://telbib.eso.org/detail.php?id=47888 http://telbib.eso.org/detail.php?id=47887 Instruments: X-SHOOTER
ProgramIDs: 086.A-0660, 089.A-0739
BibCode: 2013ApJ...768..166J

We present the discovery of a Type Ia supernova (SN) at redshift z = 1.914 from the CANDELS multi-cycle treasury program on the Hubble Space Telescope (HST). This SN was discovered in the infrared using the Wide-Field Camera 3, and it is the highest-redshift Type Ia SN yet observed. We classify this object as a SN Ia by comparing its light curve and spectrum with those of a large sample of Type Ia and core-collapse SNe. Its apparent magnitude is consistent with that expected from the ΛCDM concordance cosmology. We discuss the use of spectral evidence for classification of z > 1.5 SNe Ia using HST grism simulations, finding that spectral data alone can frequently rule out SNe II, but distinguishing between SNe Ia and SNe Ib/c can require prohibitively long exposures. In such cases, a quantitative analysis of the light curve may be necessary for classification. Our photometric and spectroscopic classification methods can aid the determination of SN rates and cosmological parameters from the full high-redshift CANDELS SN sample. ]]> http://telbib.eso.org/detail.php?id=47887 http://telbib.eso.org/detail.php?id=47886 Instruments: X-SHOOTER
ProgramIDs: 084.A-0360
BibCode: 2013ApJ...768..173H

Unusual extinction curves of high-redshift QSOs have been taken as evidence that dust is primarily produced by supernovae at high redshift. In particular, the 3000 Å Todini-Ferrara-Maiolino kink in the extinction curve of the z = 6.20 SDSS J1048+4637 has been attributed to supernova dust. Here we discuss the challenges in inferring robust extinction curves of high-redshift QSOs and critically assess previous claims of detection of supernova dust. In particular, we address the sensitivity to the choice of intrinsic QSO spectrum, the need for a long wavelength baseline, and the drawbacks in fitting theoretical extinction curves. In a sample of 21 QSOs at z ~ 6 we detect significant ultraviolet extinction using existing broadband optical, near-infrared, and Spitzer photometry. The median extinction curve is consistent with a Small Magellanic Cloud curve with A 1450 ~ 0.7 mag and does not exhibit any conspicuous (rest frame) 2175 Å or 3000 Å features. For two QSOs, SDSS J1044–0125 at z = 5.78 and SDSS J1030+0524 at z = 6.31, we further present X-shooter spectra covering the wavelength range 0.9-2.5 μm. The resulting non-parametric extinction curves do not exhibit the 3000 Å kink. Finally, in a re-analysis of literature spectra of SDSS J1048+4637, we do not find evidence for a conspicuous kink. We conclude that the existing evidence for a 3000 Å feature is weak and that the overall dust properties at high and low redshifts show no significant differences. This, however, does not preclude supernovae from dominating the dust budget at high redshift. Based on observations collected at the European Southern Observatory, Paranal, Chile (ESO programme ID 084.D-0360(A)). ]]> http://telbib.eso.org/detail.php?id=47886 http://telbib.eso.org/detail.php?id=47865 Instruments: UVES
ProgramIDs: 65.L-0507
BibCode: 2013ApJ...768L..13P

The ratios of elemental abundances observed in metal-poor stars of the Galactic halo provide a unique present-day record of the nucleosynthesis products of its earliest stars. While the heaviest elements were synthesized by the r- and s-processes, dominant production mechanisms of light trans-ironic elements were obscure until recently. This work investigates further our 2011 conclusion that the low-entropy regime of a high-entropy wind (HEW) produced molybdenum and ruthenium in two moderately metal-poor turnoff stars that showed extreme overabundances of those elements with respect to iron. Only a few, rare nucleosynthesis events may have been involved. Here we determine abundances for Mo, Ru, and other trans-Fe elements for 28 similar stars by matching spectral calculations to well-exposed near-UV Keck HIRES spectra obtained for beryllium abundances. In each of the 26 turnoff stars with Mo or Ru line detections and no evidence for s-process production (therefore old), we find Mo and Ru to be three to six times overabundant. In contrast, the maximum overabundance is reduced to factors of three and two for the neighboring elements zirconium and palladium. Since the overproduction peaks sharply at Mo and Ru, a low-entropy HEW is confirmed as its origin. The overabundance level of the heavy r-process elements varies significantly, from none to a factor of four, but is uncorrelated with Mo and Ru overabundances. Despite their moderate metallicity, stars in this group trace the products of different nucleosynthetic events: possibly very few events, possibly events whose output depended on environment, metallicity, or time. ]]> http://telbib.eso.org/detail.php?id=47865 http://telbib.eso.org/detail.php?id=47852 Instruments: HAWK-I
ProgramIDs: 60.A-9283
BibCode: 2013MNRAS.431.1252B

We present Hubble Space Telescope (HST) Wide-Field Camera 3 (WFC3) images of the merger remnant NGC 7252. In particular, we focus on the surface brightness profiles and effective radii Reff of 36 young massive clusters (YMCs) within the galaxy. All the clusters have masses exceeding 105 M&sun; and are, despite the 64 Mpc distance to the galaxy, (partly) resolved on the HST images. Effective radii can be measured down to ˜2.5 pc, and the largest clusters have Reff approaching 20 pc. The median Reff of our sample clusters is ˜ 6-7 pc, which is larger than typical radii of YMCs (˜2.5 pc). This could be due to our sample selection (only selecting resolved sources) or to an intrinsic mass-radius relation within the cluster population. We find at least three clusters that have power-law profiles of the Elson, Fall and Freeman (EFF) type extending out to ≳ 150 pc. Among them are the two most massive clusters, W3 and W30, which have profiles that extend to at least 500 and 250 pc, respectively. Despite their extended profiles, the effective radii of the three clusters are 17.2, 12.6 and 9.1 pc for W3, W26 and W30, respectively. We compare these extended profiles with those of YMCs in the Large Magellanic Cloud (R136 in 30 Dor), the Antennae galaxies (Knot S) and in the nearby spiral galaxy NGC 6946. Extended profiles seem to be a somewhat common feature, even though many nearby YMCs show distinct truncations. A continuous distribution between these two extremes, i.e. truncated or extremely extended, is the most likely interpretation. We suggest that the presence or absence of an extended envelope in very young clusters may be due to the gas distribution of the proto-cluster giant molecular cloud, in particular if the proto-cluster core becomes distinct from the surrounding gas before star formation begins. ]]> http://telbib.eso.org/detail.php?id=47852 http://telbib.eso.org/detail.php?id=47851 Instruments: ISAAC
ProgramIDs: 64.P-0500, 63.P-0391, 65.P-0579
BibCode: 2013ApJ...768L...3H

We present spatially resolved spectropolarimetric measurements of the 100 kpc scale gaseous environment of the z = 2.34 radio galaxy TXS 0211–122. The polarization level of the narrow Lyα emission is low centrally (P < 5%), but rises to P = 16.4% ± 4.6% in the eastern part of the nebula, indicating that the nebula is at least partly powered by the scattering of Lyα photons by H I. Not only is this the first detection of polarized Lyα around a radio-loud active galaxy, it is also the second detection to date for any kind of Lyα nebula. We also detect a pair of diametrically opposed UV continuum sources along the slit, at the outer edges of the Lyα nebula, which we suggest may be the limb of a dusty shell, related to the large-scale H I absorbers often associated with high-z radio galaxies. ]]> http://telbib.eso.org/detail.php?id=47851 http://telbib.eso.org/detail.php?id=47846 Instruments: UVES
ProgramIDs: 67.A-0078, 69.A-0613, 083.A-0042, 085.A-0109
BibCode: 2013MNRAS.431.1625C

The relative abundances of the Fe-peak elements (Ti-Zn) at the lowest metallicities are intimately linked to the physics of core-collapse supernova explosions. With a sample of 25 very metal poor damped Lyα systems (DLAs), we investigate the trends of the Fe-peak element ratios with metallicity. For nine of the 25 DLAs, a direct measurement (or useful upper limit) of one or more of the Ti, Cr, Co, Ni, Zn/Fe abundance ratios could be determined from detected absorption lines. For the remaining systems (without detections), we devised a new form of spectral stacking to estimate the typical Fe-peak element ratios of the DLA population in this metallicity regime. We compare these data to analogous measurements in metal-poor stars of the Galactic halo and to detailed calculations of explosive nucleosynthesis in metal-free stars. We conclude that most of the DLAs in our sample were enriched by stars that released an energy of ≲1.2 × 1051 erg when they exploded as core-collapse supernovae. Finally, we discuss the exciting prospect of measuring Fe-peak element ratios in DLAs with Fe/H < 1/1000 of solar when 30-m class telescopes become available. Only then will we be able to pin down the energy that was released by the supernovae of the first stars. ]]> http://telbib.eso.org/detail.php?id=47846 http://telbib.eso.org/detail.php?id=47799 Instruments: CES, HARPS
ProgramIDs: 072.C-0513, 073.C-0784, 074.C-0012, 076.C-0878, 077.C-0530, 078.C-0833, 079.C-0681, 71.C-0599, 70.C-0047, 69.C-0723, 67.C-0296, 66.C-0482, 64.L-0568, 62.L-0490, 072.C-0488
BibCode: 2013A&A...552A..78Z

Context. In 1992 we began a precision radial velocity survey for planets around solar-like stars with the Coudé Echelle Spectrograph and the Long Camera (CES LC) at the 1.4 m telescope in La Silla (Chile) resulting in the discovery of the planet ι Hor b. We have continued the survey with the upgraded CES Very Long Camera (VLC) and the HARPS spectrographs, both at the 3.6 m telescope, until 2007. Aims: In this paper we present additional radial velocities for 31 stars of the original sample with higher precision. The observations cover a time span of up to 15 years and permit a search for Jupiter analogues. Methods: The survey was carried out with three different instruments/instrument configurations using the iodine absorption cell and the ThAr methods for wavelength calibration. We combine the data sets and perform a joint analysis for variability, trends, and periodicities. We compute Keplerian orbits for companions and detection limits in case of non-detections. Moreover, the HARPS radial velocities are analysed for correlations with activity indicators (CaII H&K and cross-correlation function shape). Results: We achieve a long-term RV precision of 15 m/s (CES+LC, 1992-1998), 9 m/s (CES+VLC, 1999-2006), and 2.8 m/s (HARPS, 2003-2009, including archive data), respectively. This enables us to confirm the known planetary signals in ι Hor and HR 506 as well as the three known planets around HR 3259. A steady RV trend for ɛ Ind A can be explained by a planetary companion and calls for direct imaging campaigns. On the other hand, we find previously reported trends to be smaller for β Hyi and not present for α Men. The candidate planet ɛ Eri b was not detected despite our better precision. Also the planet announced for HR 4523 cannot be confirmed. Long-term trends in several of our stars are compatible with known stellar companions. We provide a spectroscopic orbital solution for the binary HR 2400 and refined solutions for the planets around HR 506 and ι Hor. For some other stars the variations could be attributed to stellar activity, as e.g. the magnetic cycle in the case of HR 8323. Conclusions: The occurrence of two Jupiter-mass planets in our sample is in line with the estimate of 10% for the frequency of giant planets with periods smaller than 10 yr around solar-like stars. We have not detected a Jupiter analogue, while the detections limits for circular orbits indicate at 5 AU a sensitivity for minimum mass of at least 1MJup (2MJup) for 13% (61%) of the stars. Based on observations collected at the European Southern Observatory, La Silla Chile, ESO programmes 50.7-0095, 51.7-0054, 52.7-0002, 53.7-0064, 54.E-0424, 55.E-0361, 56.E-0490, 57.E-0142, 58.E-0134, 59.E-0597, 60.E-0386, 61.E-0589, 62.L-0490, 64.L-0568, 66.C-0482, 67.C-0296, 69.C-0723, 70.C-0047, 71.C-0599, 072.C-0513, 073.C-0784, 074.C-0012, 076.C-0878, 077.C-0530, 078.C-0833, 079.C-0681. Also based on data obtained from the ESO Science Archive Facility.Appendices are available in electronic form at http://www.aanda.orgTables of the radial velocities, bisector spans, and log R'_HK are available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/552/A78 ]]> http://telbib.eso.org/detail.php?id=47799 http://telbib.eso.org/detail.php?id=47830 Instruments: EMMI, FORS1, FORS2, SOFI
ProgramIDs: 075.B-0220, 077.B-0599, 70.B-0585, 71.B-0602
BibCode: 2013MNRAS.431..102M

We present deep optical and near-infrared (NIR) UBVRIHKs imaging data for 24 blue compact galaxies (BCGs). The individual exposure times are on average ˜40 min in the optical (B) and ˜90 min in the NIR, but on occasion up to ˜5 h for a single target and filter, observed with 2.5, 3.5, 8.2-m telescopes. The sample contains luminous dwarf and intermediate-mass BCGs which are predominantly metal poor, although a few have near-solar metallicities. We have analysed isophotal and elliptical integration surface brightness and colour profiles, extremely deep (μB ≲ 29 mag arcsec-2) contour maps and RGB images for each galaxy in the sample, and provide a morphological classification where such is missing. Separating the burst from the underlying host we find that regardless of the total luminosity the host galaxy has the properties of a low surface brightness (LSB) dwarf with MB ≳ -18. For a number of galaxies we discover a distinct LSB component dominant around and beyond the Holmberg radius. For the specific case of ESO 400-43A&B we detect an optical bridge between the two companion galaxies at the μV ˜ 28th mag arcsec-2 isophotal level. Synthetic disc tests are performed to verify that we can trace such faint components with negligible errors down to μB = 28 and μK = 23 mag arcsec-2. By examining the structural parameters (central surface brightness μ0 and scalelength hr) derived from two radial ranges typically assumed to be dominated by the underlying host galaxy, we demonstrate the importance of sampling the host well away from the effects of the burst. We find that μ0 and hr of the BCGs host deviate from those of dwarf ellipticals (dEs) and dwarf irregulars (dI) solely due to a strong burst contribution to the surface brightness profile almost down to the Holmberg radius. Structural parameters obtained from a fainter region, μB = 26-28 mag arcsec-2, are consistent with those of true LSB galaxies for the starbursting BCGs in our sample, and with dEs and dIs for the BCGs with less vigorous star formation. ]]> http://telbib.eso.org/detail.php?id=47830 http://telbib.eso.org/detail.php?id=47836 Instruments: EFOSC2_NTT
ProgramIDs: 184.D-1140
BibCode: 2013ApJ...767..166G

We present a study of SN 2009js in NGC 918. Multi-band Kanata optical photometry covering the first ~120 days shows the source to be a Type IIP SN. Reddening is dominated by that due to our Galaxy. One-year-post-explosion photometry with the New Technology Telescope and a Subaru optical spectrum 16 days post-discovery both imply a good match with the well-studied subluminous SN 2005cs. The plateau-phase luminosity of SN 2009js and its plateau duration are more similar to the intermediate luminosity IIP SN 2008in. Thus, SN 2009js shares characteristics with both subluminous and intermediate luminosity supernovae (SNe). Its radioactive tail luminosity lies between SN 2005cs and SN 2008in, whereas its quasi-bolometric luminosity decline from peak to plateau (quantified by a newly defined parameter Δlog{L}, which measures adiabatic cooling following shock breakout) is much smaller than both the others'. We estimate the ejected mass of 56Ni to be low (~0.007 M &sun;). The SN explosion energy appears to have been small, similar to that of SN 2005cs. SN 2009js is the first subluminous SN IIP to be studied in the mid-infrared. It was serendipitously caught by Spitzer at very early times. In addition, it was detected by WISE 105 days later with a significant 4.6 μm flux excess above the photosphere. The infrared excess luminosity relative to the photosphere is clearly smaller than that of SN 2004dj, which has been extensively studied in the mid-infrared. The excess may be tentatively assigned to heated dust with mass ~3 × 10–5 M &sun;, or to CO fundamental emission as a precursor to dust formation. ]]> http://telbib.eso.org/detail.php?id=47836 http://telbib.eso.org/detail.php?id=47832 Instruments: EFOSC2_NTT, NACO, SOFI
ProgramIDs: 089.D-0305, 188.D-3003
BibCode: 2013MNRAS.431L.102M

We present the identification of the progenitor of the Type IIP SN 2012ec in archival pre-explosion Hubble Space Telescope Wide Field Planetary Camera 2 (WFPC2) and Advanced Camera for Surveys Wide Field Channel F814W images. The properties of the progenitor are further constrained by non-detections in pre-explosion WFPC2 F450W and F606W images. We report a series of early photometric and spectroscopic observations of SN 2012ec. The r'-band light curve shows a plateau with M_{r^' }}=-17.0. The early spectrum is similar to the Type IIP SN 1999em, with the expansion velocity measured at Hα absorption minimum of -11 700 km s-1 (at 1 d post-discovery). The photometric and spectroscopic evolution of SN 2012ec shows it to be a Type IIP SN, discovered only a few days post-explosion (<6 d). We derive a luminosity for the progenitor, in comparison with MARCS model spectral energy distributions, of log {L/L}_{&sun;} = 5.15± 0.19, from which we infer an initial mass range of 14-22 M&sun;. This is the first SN with an identified progenitor to be followed by the Public ESO Spectroscopic Survey of Transient Objects (PESSTO). ]]> http://telbib.eso.org/detail.php?id=47832 http://telbib.eso.org/detail.php?id=47805 Instruments: FEROS2.2, HARPS
ProgramIDs: 072.C-0488, 073.D-0578, 075.C-0332, 082.C-0312, 080.D-0408, 60.A-9036, 083.A-9011, 60.A-9700, 074.D-0086, 084.A-9004, 080.A-9021, 083.A-9003, 077.C-0573, 083.A-9013, 085.C-0743, 079.A-9013, 085.A-9027, 077.C-0766
BibCode: 2013A&A...552A..73N

Context. In some recent works, the C/O abundance ratio in high-metallicity stars with planets is found to vary by more than a factor of two, i.e. from ~0.4 to C/O ≳ 1. This has led to discussions about the existence of terrestrial planets with a carbon-dominated composition that is very different from the composition of the Earth. Aims: The mentioned C/O values were obtained by determining carbon abundances from high-excitation C I lines and oxygen abundances from the forbidden [O i] line at 6300 Å. This weak line is, however, strongly affected by a nickel blend at high metallicities. Aiming for more precise C/O ratios, oxygen abundances in this paper are derived from the high-excitation O I triplet at 7774 Å. Methods: The C I lines at 5052 and 5380 Å in HARPS spectra were applied to determine carbon abundances of 33 solar-type stars for which FEROS spectra are available for determining oxygen abundances from the O iλ7774 triplet. Differential abundances with respect to the Sun were derived from equivalent widths using MARCS model atmospheres. Non-LTE corrections were included, and the analysis was carried out with both spectroscopic and photometric estimates of stellar effective temperatures and surface gravities. Results: The results do not confirm the high C/O ratios previously found. C/O shows a tight, slightly increasing dependence on metallicity, i.e. from C/O ≃ 0.58 at [Fe/H] = 0.0 to C/O ≃ 0.70 at [Fe/H] = 0.4 with an rms scatter of only 0.06. Conclusions: Recent findings of C/O ratios higher than 0.8 in high-metallicity stars seem to be spurious due to statistical errors in estimating the strength of the weak [O i] line in the Ni I blended λ6300 feature. Assuming that the composition of a proto-planetary disk is the same as that of the host star, the C/O values found in this paper lend no support to the existence of carbon-rich planets. The small scatter of C/O among thin-disk stars suggests that the nucleosynthesis products of Type II supernovae and low- to intermediate-mass stars are well mixed in the interstellar medium. Based on data products from observations made with ESO Telescopes at the La Silla Paranal Observatory under programmes given in Table 1.Tables 1 and 4 are available in electronic form at http://www.aanda.org ]]> http://telbib.eso.org/detail.php?id=47805 http://telbib.eso.org/detail.php?id=47802 Instruments:
ProgramIDs: 66.D-0538
BibCode: 2013AN....334..237L

We present relative astrometry and differential photometry measurements for a sample of nearby southern orbital binaries making use of the technique of Adaptive Optics. The observations were made in December 2000, with the ADONIS camera mounted at the 3.6-m ESO telescope from La Silla Observatory, equipped with the broad-band near-infrared filters (J-, H-, K-passbands). Our sample contains stars which do not fit very well the empirical mean mass-luminosity relation (according to our previous study), but for which accurate parallaxes (determined by the Hipparcos satellite) and high-quality orbits were available thanks to many previous efforts. We derived accurate positions and J, H, K magnitudes of the individual components of those binaries. The individual stellar components have near-infrared colour indices well grouped in those plots and are comparable to standard single stars. Based on observations made at the 3.6-m telescope, ESO, La Silla (P66.D-0538) ]]> http://telbib.eso.org/detail.php?id=47802 http://telbib.eso.org/detail.php?id=47793 Instruments: FEROS2.2
ProgramIDs: 086.D-0576
BibCode: 2013A&A...552A..60M

Pulsating stars in eclipsing binary systems are powerful tools to test stellar models. Binarity enables us to constrain the pulsating component's physical parameters and this knowledge drastically improves the input physics for asteroseismic studies. The study of stellar oscillations then allows us to improve our understanding of stellar interiors and stellar evolution. The space mission CoRoT discovered several promising objects suitable for these studies. They were photometrically observed with unprecedented accuracy, but needed spectroscopic follow-up. A promising target was the relatively bright eclipsing system CoRoT 102918586, which turned out to be a double-lined spectroscopic binary and also showed clear evidence of γ Dor type pulsations. With the aim of combining the information from binarity and pulsation and fully exploiting the potential of CoRoT photometry we obtained phase resolved high-resolution spectroscopy with the Sandiford spectrograph at the McDonald 2.1m telescope and the FEROS spectrograph at the ESO 2.2 m telescope. Spectroscopy yielded both the radial velocity curves and, after spectra disentangling, the component effective temperatures, metallicity, and line-of-sight projected rotational velocities. The CoRoT light curve was analyzed with an iterative procedure, devised to disentangle eclipses from pulsations. The eclipsing binary light curve analysis, combined with the spectroscopic results, provided an accurate determination of the system parameters, and the comparison with evolutionary models provided strict constraints on the system age. Finally, the residuals obtained after subtraction of the best-fitting eclipsing binary model were analyzed to determine the pulsator properties. We achieved a complete and consistent description of the system. The primary star pulsates with typical γ Dor frequencies and shows a splitting in period that is consistent with high order g-mode pulsations in a star of the corresponding physical parameters. The value of the splitting, in particular, is consistent with pulsations in ℓ = 1 modes. Based on photometry collected by the CoRoT space mission and spectroscopy obtained with the Sandiford spectrograph attached at the 2.1 m telescope at McDonald Observatory, USA and the FEROS spectrograph attached to the ESO 2.2 m telescope at ESO, La Silla, Chile. The CoRoT space mission was developed and is operated by the French space agency CNES, with participation of ESA's RSSD and Science Programs, Austria, Belgium, Brazil, Germany and Spain.McDonald spectra, light curves, and the two disentangled spectra are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/552/A60 ]]> http://telbib.eso.org/detail.php?id=47793 http://telbib.eso.org/detail.php?id=47784 Instruments: NACO
ProgramIDs: 075.D-0268
BibCode: 2013MNRAS.430.3112M

We investigate the circumstellar dust properties of the oxygen-rich bipolar proto-planetary nebula (PPN) IRAS 18276-1431 by means of two-dimensional radiative transfer simulations of the circumstellar dust shell. The model geometry is assumed to have a torus and an envelope which consists of a pair of bipolar lobes and a spherical asymptotic giant branch shell. The parameters of the dust and the dust shell are constrained by comparing the spectral energy distribution (SED) and near-infrared intensity and polarization data with the models. The polarization in the envelope reaches 50-60 per cent and is nearly constant in the H and KS bands in the observations. This weak wavelength dependence of the polarization can be reproduced with a grain-size distribution function for the torus: 0.05 μm ≤ a with n(a)∝a- (p = 5.5)exp ( - a/ac = 0.3 μm). The power index p is significantly steeper than that for interstellar dust (p ˜ 3). Similar results have also been found in some other PPNs and suggest that mechanisms that grind down large particles, such as sputtering, may also have acted when the dust particles formed. The spectral opacity index β is found to be 0.6 ± 0.5 from the 760 μm to 2.6 mm fluxes, which is characterized by the dust in the torus. This low value (<2) indicates the presence of large dust grains in the torus. We discuss two possible dust models for the torus. One has a size distribution function of 1.0 ≤ a ≤ amax = 5 000.0 μm with n(a) ∝ a-(p = 2.5) and the other is 1.0 μm ≤ a ≤ amax = 10 000.0 μm with n(a) ∝ a-(p = 3.5). The former has β of 0.633, but we are not able to find reasonable geometry parameters to fit the SED in the infrared. The latter has β of 1.12, but reproduces the SED better over a wide wavelength range. With this dust model, the geometric parameters are estimated as follows: the inner and outer radii are 30 and 1000 au and the torus mass is 3.0 M&sun;. Given that the torii are generally not found to be rotating, a large fraction of the torus material is likely to be expanding. Assuming an expansion velocity of 15 km s-1, the torus formation time and mass-loss rate are found to be ˜300 yr and ˜10-2 M&sun; yr-1, respectively. ]]> http://telbib.eso.org/detail.php?id=47784 http://telbib.eso.org/detail.php?id=47825 Instruments: FLAMES-UV, UVES
ProgramIDs: 65.L-0165, 165.L-0263, 073.D-0211, 080.D-0368, 083.D-0208, 266.D-5655
BibCode: 2013ApJ...766...78M

GALA is a freely distributed Fortran code for automatically deriving the atmospheric parameters (temperature, gravity, microturbulent velocity, and overall metallicity) and abundances for individual species of stellar spectra using the classical method based on the equivalent widths of metallic lines. The abundances of individual spectral lines are derived by using the WIDTH9 code developed by R. L. Kurucz. GALA is designed to obtain the best model atmosphere by optimizing temperature, surface gravity, microturbulent velocity, and metallicity after rejecting the discrepant lines. Finally, it computes accurate internal errors for each atmospheric parameter and abundance. GALA is suitable for analyzing both early- and late-type stars, under the assumption of local thermodynamical equilibrium. The code permits us to obtain chemical abundances and atmospheric parameters for large stellar samples in a very short time, thus making GALA a useful tool in the epoch of multi-object spectrographs and large surveys. An extensive set of tests with both synthetic and observed spectra is performed and discussed to explore the capabilities and robustness of the code. Based on observations collected at the ESO-VLT under programs 65.L-0165, 165.L-0263, 073.D-0211, 080.D-0368, 083.D-0208, and 266.D-5655 and on data available in the ELODIE archive. This research has also made use of the SIMBAD database, operated at CDS, Strasbourg, France. ]]> http://telbib.eso.org/detail.php?id=47825 http://telbib.eso.org/detail.php?id=47819 Instruments: FLAMES-GIRAFFE
ProgramIDs: 083.B-0336
BibCode: 2013MNRAS.430.2097J

Using VLT/Fibre Large Array Multi Element Spectrograph (FLAMES) optical integral field unit observations, we present the first spatially resolved spectroscopic study of the well-known blue compact galaxy Haro 11, thought to be a local analogue to high-redshift Lyman break galaxies. Haro 11 displays complex emission line profiles, consisting of narrow (full width at half-maximum, FWHM ≲ 200 km s-1) and broad (FWHM ˜ 200-300 km s-1) components. We identify three distinct emission knots kinematically connected to one another. A chemodynamical analysis is presented, revealing that spatially resolved ionic and elemental abundances do not agree with those derived from integrated spectra across the galaxy. We conclude that this is almost certainly due to the surface brightness weighting of electron temperature in integrated spectra, leading to higher derived abundances. We find that the eastern knot has a low gas density, but a higher temperature (by ˜4000 K) and consequently an oxygen abundance ˜0.4 dex lower than the neighbouring regions. A region of enhanced N/O is found specifically in Knot C, confirming previous studies that found anomalously high N/O ratios in this system. Maps of the Wolf-Rayet (WR) feature at 4686 Å reveal large WR populations (˜900-1500 stars) in Knots A and B. The lack of WR stars in Knot C combined with an age of ˜7.4 Myr suggests that a recently completed WR phase may be responsible for the observed N/O excess. Conversely, the absence of N-enriched gas and strong WR emission in Knots A and B suggests that we are observing these regions at an epoch where stellar ejecta has yet to cool and mix with the interstellar medium. ]]> http://telbib.eso.org/detail.php?id=47819 http://telbib.eso.org/detail.php?id=47809 Instruments: HARPS
ProgramIDs: 072.D-0707
BibCode: 2013MNRAS.430.1709M

Stellar activity, such as starspots, can induce radial velocity (RV) variations that can mask or even mimic the RV signature of orbiting exoplanets. For this reason RV exoplanet surveys have been unsuccessful when searching for planets around young, active stars and are therefore failing to explore an important regime which can help to reveal how planets form and migrate. This paper describes a new technique to remove spot signatures from the stellar line-profiles of moderately rotating, active stars (v sin i ranging from 10 to 50 km s-1). By doing so it allows planetary RV signals to be uncovered. We used simulated models of a G5V type star with differing dark spots on its surface along with archive data of the known active star HD 49933 to validate our method. The results showed that starspots could be effectively cleaned from the line-profiles so that the stellar RV jitter was reduced by more than 80 per cent. Applying this procedure to the same models and HD 49933 data, but with fake planets injected, enabled the effective removal of starspots so that Jupiter mass planets on short orbital periods were successfully recovered. These results show that this approach can be useful in the search for hot-Jupiter planets that orbit around young, active stars with a v sin i of ˜10-50 km s-1. ]]> http://telbib.eso.org/detail.php?id=47809 http://telbib.eso.org/detail.php?id=47807 Instruments: CRIRES
ProgramIDs: 088.C-0595
BibCode: 2013Icar..223..741M

We analyse ground-based infrared observations of H3+ emission from the upper atmosphere of Uranus using Gemini North/GNIRS, NASA IRTF/SpeX and VLT/CRIRES. These observations were obtained on 15 different nights in late 2011, between day-of-year 251 (5th of September) and 340 (6th of December). The equinox of Uranus occurred in late 2007 and these recent observations quantify the behaviour of the planet's upper atmosphere 4 years after equinox, equivalent to 15° of circumsolar rotation.The mean temperature of the ionosphere from these measurements is 520 ± 32 K, which is cooler than any of the temperatures determined by the precursor to this study (Melin, H., Stallard, T., Miller, S., Trafton, L.M., Encrenaz, T., Geballe, T.R. [2011b]. Astrophys. J. 729, 134). Thus, the cooling trend that has been observed since the first H3+ observation in 1992 has continued, even as the planet traversed equinox. This suggests that the driver of the elevated thermospheric temperatures cannot be linked to purely seasonal mechanisms, and we consider other sources of variability, such as the changing geometry between the planet, magnetosphere and solar wind. ]]> http://telbib.eso.org/detail.php?id=47807 http://telbib.eso.org/detail.php?id=47877 Instruments: EFOSC2_3.6, FORS2
ProgramIDs: 69.D-0143, 70.D-0227, 71.D-0296, 71.D-0552
BibCode: 2013A&A...553A..12N

Many different classes of X-ray sources contribute to the Galactic landscape at high energies. Although the nature of the most luminous X-ray emitters is now fairly well understood, the population of low-to-medium X-ray luminosity (LX = 1027-34 erg s-1) sources remains much less studied, our knowledge being mostly based on the observation of local members. The advent of wide field and high sensitivity X-ray telescopes such as XMM-Newton now offers the opportunity to observe this low-to-medium LX population at large distances. We report on the results of a Galactic plane survey conducted by the XMM-Newton Survey Science Centre (SSC). Beyond its astrophysical goals, this survey aims at gathering a representative sample of identified X-ray sources at low latitude that can be used later on to statistically identify the rest of the serendipitous sources discovered in the Milky Way. The survey is based on 26 XMM-Newton observations, obtained at | b | < 20 deg, distributed over a large range in Galactic longitudes and covering a summed area of 4 deg2. The flux limit of our survey is 2 × 10-15 erg cm-2 s-1 in the soft (0.5-2 keV) band and 1 × 10-14 erg cm-2 s-1 in the hard (2-12 keV) band. We detect a total of 1319 individual X-ray sources. Using optical follow-up observations supplemented by cross-correlation with a large range of multi-wavelength archival catalogues we identify 316 X-ray sources. This constitutes the largest group of spectroscopically identified low latitude X-ray sources at this flux level. The majority of the identified X-ray sources are active coronae with spectral types in the range A-M at maximum distances of ~1 kpc. The number of identified active starsincreases towards late spectral types, reaching a maximum at K. Using infrared colours we classify 18% of the stars as giants. The observed distributions of FX/FV, X-ray and infrared colours indicates that our sample is dominated by a young (100 Myr) to intermediate (600 Myr) age population with a small contribution of close main sequence or evolved binaries. We find other interesting objects such as cataclysmic variables (d ~ 0.6-2 kpc), low luminosity high mass stars (likely belonging to the class of γ-Cas-like systems, d ~ 1.5-7 kpc), T Tauri and Herbig-Ae stars. A handful of extragalactic sources located in the highest Galactic latitude fields could be optically identified. For the 20 fields observed with the EPIC pn camera, we have constructed log N(>S) - log S curves in the soft and hard bands. In the soft band, the majority of the sources are positively identified with active coronae and the fraction of stars increases by about one order of magnitude from b = 60° to b = 0° at an X-ray flux of 2 × 10-14 erg cm-2 s-1. The hard band is dominated by extragalactic sources, but there is a small contribution from a hard Galactic population formed by CVs, HMXB candidates or γ-Cas-like systems and by some active coronae that are also detected in the soft band. At b = 0° the surface density of hard sources brighter than 1 × 10-13 erg cm-2 s-1 steeply increases by one order of magnitude from l = 20° to the Galactic centre region (l = 0.9°). Based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA. Based on observations carried out at the European Southern Observatory, La Silla and Paranal, Chile under programmes Nos 69.D-0143, 70.D-0227, 71.D-0296, 71.D-0552. Based on observations obtained at the Canada-France-Hawaii Telescope (CFHT) which is operated by the National Research Council of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique of France, and the University of Hawaii. Based on observations obtained at the Observatoire de Haute Provence which is operated by the Centre National de la Recherche Scientifique of France. Tables 8-33 are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (<ext-link ext-link-type="ftp" xlink:href="ftp://130.79.128.5">130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/553/A12 ]]> http://telbib.eso.org/detail.php?id=47877 http://telbib.eso.org/detail.php?id=47779 Instruments: X-SHOOTER
ProgramIDs: 085.A-0009
BibCode: 2013MNRAS.430.2739H

For gamma-ray burst 100901A, we have obtained Gemini-North and Very Large Telescope optical afterglow spectra at four epochs: 1 h, 1 d, 3 d and 1 week after the burst, thanks to the afterglow remaining unusually bright at late times. Apart from a wealth of metal resonance lines, we also detect lines arising from fine-structure levels of the ground state of Fe II, and from metastable levels of Fe II and Ni II at the host redshift (z = 1.4084). These lines are found to vary significantly in time. The combination of the data and modelling results shows that we detect the fall of the Ni II 4F9/2 metastable level population, which to date has not been observed. Assuming that the population of the excited states is due to the ultraviolet radiation of the afterglow, we estimate an absorber distance of a few hundred pc. This appears to be a typical value when compared to similar studies. We detect two intervening absorbers (z = 1.3147, 1.3179). Despite the wide temporal range of the data, we do not see significant variation in the absorption lines of these two intervening systems. ]]> http://telbib.eso.org/detail.php?id=47779 http://telbib.eso.org/detail.php?id=47816 Instruments: AMBER
ProgramIDs: 081.C-0794, 083.C-0146, 083.C-0236, 084.C-0983, 084.C-0905
BibCode: 2013MNRAS.430.1839G

Active pre-main-sequence binaries with separations of around 10 stellar radii present a wealth of phenomena unobserved in common systems. The study of these objects is extended from classical T Tauri stars to the Herbig Ae star HD 104237. The primary has a mass 2.2 ± 0.2 M&sun; and secondary 1.4 ± 0.3 M&sun;. Spectrointerferometry with the VLTI/AMBER in the K-band continuum and the Brγ line is presented. It is found that the K-band continuum squared visibilities are compatible with a circumbinary disc with a radius of ˜0.5 AU. However, a significant fraction (˜50 per cent) of the flux is unresolved and not fully accounted by the stellar photospheres. The stars probably do not hold circumstellar discs, in addition to the circumbinary disc, due to the combined effects of inner magnetospheric truncation and outer tidal truncation. This unresolved flux likely arises in compact structures inside the tidally disrupted circumbinary disc. Most (≳90 per cent) of the Brγ line emission is unresolved. The line-to-continuum spectroastrometry shifts in time, along the direction of the Lyα jet known to be driven by the system. The shift is anticorrelated with the Brγ equivalent width. It is shown that the unresolved Brγ emission cannot originate in the jet but instead is compatible with stellar emission from the orbiting binary components. The increase in the absolute value of the equivalent width of the line takes place at periastron passage; it could arise in an accretion burst, a flare or in the increase in effective size of the emission region by the interaction of the magnetospheres. The binary longitude of the ascending node is found to be Ω = (235 ± 3)° and the orbit retrograde. The origin of the jet is revisited. The tidal disruption of the circumstellar discs creates difficulties to ejection models that rely on stellar magnetosphere and disc coupling. A scenario of a stellar wind collimated by a circumbinary disc wind is suggested. ]]> http://telbib.eso.org/detail.php?id=47816 http://telbib.eso.org/detail.php?id=47818 Instruments: MIDI
ProgramIDs: 274.C-5026, 076.C-0736
BibCode: 2013A&A...552A..62M

Context. It is hypothesized that low-mass young stellar objects undergo eruptive phases during their early evolution. These eruptions are thought to be caused by highly increased mass accretion from the disk onto the star, and therefore play an important role in the early evolution of Sun-like stars, of their circumstellar disks (structure, dust composition), and in the formation of their planetary systems. The outburst of V1647 Ori between 2003 and 2006 offered a rare opportunity to investigate such an accretion event. Aims: By means of our interferometry observing campaign during this outburst, supplemented by other observations, we investigate the temporal evolution of the inner circumstellar structure of V1647 Ori, the region where Earth-like planets could be born. We also study the role of the changing extinction in the brightening of the object and separate it from the accretional brightening. Methods: We observed V1647 Ori with MIDI on the VLTI at two epochs in this outburst. First, during the slowly fading plateau phase (2005 March) and second, just before the rapid fading of the object (2005 September), which ended the outburst. We used the radiative transfer code MC3D to fit the interferometry data and the spectral energy distributions from five different epochs at different stages of the outburst. The comparison of these models allowed us to trace structural changes in the system on AU-scales. We also considered qualitative alternatives for the interpretation of our data. Results: We found that the disk and the envelope are similar to those of non-eruptive young stars and that the accretion rate varied during the outburst. We also found evidence for the increase of the inner radii of the circumstellar disk and envelope at the beginning of the outburst. Furthermore, the change of the interferometric visibilities indicates structural changes in the circumstellar material. We test a few scenarios to interpret these data. We also speculate that the changes are caused by the fading of the central source, which is not immediately followed by the fading of the outer regions. Conclusions: We found that most of our results fit in the canonical picture of young eruptive stars. Our study provided dynamical information from the regions of the innermost few AU of the system: changes of the inner radii of the disk and envelope. However, if the delay in the fading of the disk is responsible for the changes seen in the MIDI data, the effect should be confirmed by dynamical modeling. Based on observations made with ESO telescopes at the Paranal Observatory under program IDs 274.C-5026 and 076.C-0736. In addition, this work is based in part on archival data obtained with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. ]]> http://telbib.eso.org/detail.php?id=47818 http://telbib.eso.org/detail.php?id=47829 Instruments: EFOSC2_NTT
ProgramIDs: 088.D-0588, 089.D-0505
BibCode: 2013MNRAS.431...92T

The old nova V728 Sco has been recently recovered via photometric and spectroscopic observations, 150 yr after the nova eruption. The spectral properties pointed to a high-inclination system with a comparatively low mass-transfer rate. In this paper, we show that the object is an eclipsing system with an orbital period of 3.32 h. It has enhanced long-term variability that can be interpreted as `stunted' dwarf-nova-type outbursts. Using the ingress and egress times of the eclipsed components we calculate the radius of the central object. The latter turns out to be significantly larger than a white dwarf and we identify it with a hot inner disc. The implications for models on the behaviour of post-novae are discussed. ]]> http://telbib.eso.org/detail.php?id=47829 http://telbib.eso.org/detail.php?id=47873 Instruments: FORS1, FORS2, UVES
ProgramIDs: 66.D-0589, 70.D-0379, 074.D-0761, 078.D-0521, 080.D-0727, 082.D-0273, 086.D-0713, 088.D-0638
BibCode: 2013ApJ...768...88F

We present observations with the Very Large Telescope and Hubble Space Telescope (HST) of the broad emission lines from the inner ejecta and reverse shock of SN 1987A from 1999 February until 2012 January (days 4381-9100 after explosion). We detect broad lines from Hα, Hβ, Mg I], Na I, [O I], [Ca II], and a feature at ~9220 Å. We identify the latter line with Mg II λλ9218, 9244, which is most likely pumped by Lyα fluorescence. Hα and Hβ both have a centrally peaked component extending to ~4500 km s–1 and a very broad component extending to gsim 11, 000 km s–1, while the other lines have only the central component. The low-velocity component comes from unshocked ejecta, heated mainly by X-rays from the circumstellar environment, whereas the very broad component comes from faster ejecta passing through the reverse shock, created by the collision with the circumstellar ring. The flux in Hα from the reverse shock has increased by a factor of four to six from 2000 to 2007. After that there is a tendency of flattening of the light curve, similar to what may be seen in the optical lines from the shocked ring. The core component seen in Hα, [Ca II], and Mg II has experienced a similar increase, which is consistent with that found from HST photometry. The energy deposition of the external X-rays is calculated using explosion models for SN 1987A and we predict that the outer parts of the unshocked ejecta will continue to brighten because of this. The external X-ray illumination also explains the edge-brightened morphology of the ejecta seen in the HST images. We finally discuss evidence for dust in the ejecta from line asymmetries. ]]> http://telbib.eso.org/detail.php?id=47873 http://telbib.eso.org/detail.php?id=47874 Instruments: ALMA_Bands, LABOCA
ProgramIDs: 2011.0.00294.S, 078.F-9028, 079.F-9500, 080.A-3023, 081.F-9500
BibCode: 2013ApJ...768...91H

We present an Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 0 survey of 126 submillimeter sources from the LABOCA ECDFS Submillimeter Survey (LESS). Our 870 μm survey with ALMA (ALESS) has produced maps ~3× deeper and with a beam area ~200× smaller than the original LESS observations, doubling the current number of interferometrically-observed submillimeter sources. The high resolution of these maps allows us to resolve sources that were previously blended and accurately identify the origin of the submillimeter emission. We discuss the creation of the ALESS submillimeter galaxy (SMG) catalog, including the main sample of 99 SMGs and a supplementary sample of 32 SMGs. We find that at least 35% (possibly up to 50%) of the detected LABOCA sources have been resolved into multiple SMGs, and that the average number of SMGs per LESS source increases with LESS flux density. Using the (now precisely known) SMG positions, we empirically test the theoretical expectation for the uncertainty in the single-dish source positions. We also compare our catalog to the previously predicted radio/mid-infrared counterparts, finding that 45% of the ALESS SMGs were missed by this method. Our ~1.''6 resolution allows us to measure a size of ~9 kpc × 5 kpc for the rest-frame ~300 μm emission region in one resolved SMG, implying a star formation rate surface density of 80 M &#9737; yr–1 kpc–2, and we constrain the emission regions in the remaining SMGs to be <10 kpc. As the first statistically reliable survey of SMGs, this will provide the basis for an unbiased multiwavelength study of SMG properties. ]]> http://telbib.eso.org/detail.php?id=47874 http://telbib.eso.org/detail.php?id=47872 Instruments: NACO, SINFONI
ProgramIDs: 076.D-0558, 086.D-0713
BibCode: 2013ApJ...768...89L

We present a study of the morphology of the ejecta in Supernova 1987A based on images and spectra from the Hubble Space Telescope (HST) as well as integral field spectroscopy from VLT/SINFONI. The HST observations were obtained between 1994 and 2011 and primarily probe the outer H-rich zones of the ejecta. The SINFONI observations were obtained in 2005 and 2011 and instead probe the [Si I]+[Fe II] emission from the inner regions. We find a strong temporal evolution of the morphology in the HST images, from a roughly elliptical shape before ~5000 days, to a more irregular, edge-brightened morphology with a "hole" in the middle thereafter. This transition is a natural consequence of the change in the dominant energy source powering the ejecta, from radioactive decay before ~5000 days to X-ray input from the circumstellar interaction thereafter. The [Si I]+[Fe II] images display a more uniform morphology, which may be due to a remaining significant contribution from radioactivity in the inner ejecta and the higher abundance of these elements in the core. Both the Hα and the [Si I]+[Fe II] line profiles show that the ejecta are distributed fairly close to the plane of the inner circumstellar ring, which is assumed to define the rotational axis of the progenitor star. The Hα emission extends to higher velocities than [Si I]+[Fe II], as expected from theoretical models. There is no clear symmetry axis for all the emission. Instead, we find that the emission is concentrated to clumps and that the emission is distributed somewhat closer to the ring in the north than in the south. This north-south asymmetry may be partially explained by dust absorption. We compare our results with explosion models and find some qualitative agreement, but note that the observations show a higher degree of large-scale asymmetry. ]]> http://telbib.eso.org/detail.php?id=47872 http://telbib.eso.org/detail.php?id=47866 Instruments: AMBER
ProgramIDs: 090.D-0459
BibCode: 2013A&A...553A...3O

Aims: We present a high-spatial and high-spectral resolution observation of the well-studied K giant Aldebaran with AMBER at the Very Large Telescope Interferometer (VLTI). Our aim is to spatially resolve the outer atmosphere (so-called MOLsphere) in individual CO first overtone lines and derive its physical properties, which are important for understanding the mass-loss mechanism in normal (i.e., non-Mira) K-M giants. Methods: Aldebaran was observed between 2.28 and 2.31 μm with a projected baseline length of 10.4 m and a spectral resolution of 12 000. Results: The uniform-disk diameter observed in the CO first overtone lines is 20-35% larger than is measured in the continuum. We have also detected a signature of inhomogeneities in the CO-line-forming region on a spatial scale of ~45 mas, which is more than twice as large as the angular diameter of the star itself. While the MARCS photospheric model reproduces the observed spectrum well, the angular size in the CO lines predicted by the MARCS model is significantly smaller than observed. This is because the MARCS model with the parameters of Aldebaran has a geometrical extension of only ~2% (with respect to the stellar radius). The observed spectrum and interferometric data in the CO lines can be simultaneously reproduced by placing an additional CO layer above the MARCS photosphere. This CO layer is extended to 2.5 ± 0.3 R⋆ with CO column densities of 5 × 1019-2 × 1020 cm-2 and a temperature of 1500 ± 200 K. Conclusions: The high spectral resolution of AMBER has enabled us to spatially resolve the inhomogeneous, extended outer atmosphere (MOLsphere) in the individual CO lines for the first time in a K giant. Our modeling of the MOLsphere of Aldebaran suggests a rather small gradient in the temperature distribution above the photosphere up to 2-3 R⋆. Based on AMBER observations made with the Very Large Telescope Interferometer of the European Southern Observatory. Program ID: 090.D-0459(A). ]]> http://telbib.eso.org/detail.php?id=47866 http://telbib.eso.org/detail.php?id=47864 Instruments: AMBER, HARPS, MIDI
ProgramIDs: 088.C-0868, 088.C-0763, 082.D-0833
BibCode: 2013ApJ...768...80K

Pre-transitional disks are protoplanetary disks with a gapped disk structure, potentially indicating the presence of young planets in these systems. In order to explore the structure of these objects and their gap-opening mechanism, we observed the pre-transitional disk V1247 Orionis using the Very Large Telescope Interferometer, the Keck Interferometer, Keck-II, Gemini South, and IRTF. This allows us to spatially resolve the AU-scale disk structure from near- to mid-infrared wavelengths (1.5-13 μm), tracing material at different temperatures and over a wide range of stellocentric radii. Our observations reveal a narrow, optically thick inner-disk component (located at 0.18 AU from the star) that is separated from the optically thick outer disk (radii >~ 46 AU), providing unambiguous evidence for the existence of a gap in this pre-transitional disk. Surprisingly, we find that the gap region is filled with significant amounts of optically thin material with a carbon-dominated dust mineralogy. The presence of this optically thin gap material cannot be deduced solely from the spectral energy distribution, yet it is the dominant contributor at mid-infrared wavelengths. Furthermore, using Keck/NIRC2 aperture masking observations in the H, K', and L' bands, we detect asymmetries in the brightness distribution on scales of ~15-40 AU, i.e., within the gap region. The detected asymmetries are highly significant, yet their amplitude and direction changes with wavelength, which is not consistent with a companion interpretation but indicates an inhomogeneous distribution of the gap material. We interpret this as strong evidence for the presence of complex density structures, possibly reflecting the dynamical interaction of the disk material with sub-stellar mass bodies that are responsible for the gap clearing. Based on observations made with the Keck observatory (NASA program ID N121IV and NOAO program ID N121N2), Gemini South (NOAO program ID GS-2011B-Q-19), and with ESO telescopes at the Paranal Observatory (ESO program IDs 088.C-0868(A) and 088.C-0763(A+B)). ]]> http://telbib.eso.org/detail.php?id=47864 http://telbib.eso.org/detail.php?id=47855 Instruments: FORS1
ProgramIDs: 64.H-0624
BibCode: 2013A&A...552A.106C

Aims: The distance of NGC 1316, the brightest galaxy in the Fornax cluster, provides an interesting test for the cosmological distance scale. First, because Fornax is the second largest cluster of galaxies within ≲25 Mpc after Virgo and, in contrast to Virgo, has a small line-of-sight depth; and second, because NGC 1316 is the single galaxy with the largest number of detected Type Ia supernovae (SNe Ia), giving the opportunity to test the consistency of SNe Ia distances both internally and against other distance indicators. Methods: We measure surface brightness fluctuations (SBF) in NGC 1316 from ground- and space-based imaging data. The sample provides a homogeneous set of measurements over a wide wavelength interval. The SBF magnitudes, coupled with empirical and theoretical absolute SBF calibrations, are used to estimate the distance to the galaxy. We also present the first B-band SBF measurements of NGC 1316 and use them together with the optical and near-IR SBF data to analyze the properties of field stars in the galaxy. Results: We obtain mag, or d = 20.8 ± 0.5(stat.) ± 1.5(sys.) Mpc. When placed in a consistent Cepheid distance scale, our result agrees with the distances from other indicators. On the other hand, our distance is ~17% larger than the most recent estimate based on SNe Ia. Possible explanations for this disagreement are the uncertain level of internal extinction, and/or calibration issues. Concerning the stellar population analysis, we confirm the results from other spectro-photometric indicators: the field stars in NGC 1316 are dominated by a component with roughly solar metallicity and intermediate age. A non-negligible mismatch exists between B-band SBF models and data. We confirm that such behavior can be accounted for by an enhanced percentage of hot horizontal branch stars. Conclusions: Our study of the SBF distance to NGC 1316, and the comparison with distances from other indicators, raises some concern about the homogeneity between the calibrations of different indicators. If not properly placed in the same reference scale, significant differences can occur, with dramatic impact on the cosmological distance ladder. Our results on the stellar populations properties show that SBF data over a broad wavelength interval are an efficient means of studying the properties of unresolved systems in peculiar cases like NGC 1316. Based on data obtained from the ESO Science Archive Facility, and on observations made with the NASA/ESA Hubble Space Telescope, and obtained from the Hubble Legacy Archive, which is a collaboration between the Space Telescope Science Institute (STScI/NASA), the Space Telescope European Coordinating Facility (ST-ECF/ESA) and the Canadian Astronomy Data Centre (CADC/NRC/CSA).Appendices A and B are available in electronic form at http://www.aanda.orgReduced VLT images (as FITS files) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (<ext-link ext-link-type="ftp" xlink:href="ftp://130.79.128.5">130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/552/A106 ]]> http://telbib.eso.org/detail.php?id=47855 http://telbib.eso.org/detail.php?id=47854 Instruments: UVES
ProgramIDs: 087.D-0123
BibCode: 2013A&A...552A.107S

Context. Carbon-enhanced metal-poor stars (CEMP) form a significant proportion of the metal-poor stars, their origin is not well understood, and this carbon-enhancement appears in stars that exhibit different abundance patterns. Aims: Three very metal-poor C-rich turnoff stars were selected from the SDSS survey, observed with the ESO VLT (UVES) to precisely determine the element abundances. In turnoff stars (unlike giants) the carbon abundance has not been affected by mixing with deep layers and is therefore easier to interpret. Methods: The analysis was performed with one dimensional (1D) local thermodynamical equilibrium (LTE) static model atmospheres. When available, non-LTE corrections were applied to the classical LTE abundances. The 3D effects on the CH and CN molecular bands were computed using hydrodynamical simulations of the stellar atmosphere (CO5BOLD) and are found to be very important. Results: To facilitate a comparison with previous results, only 1D abundances are used in the discussion. The abundances (or upper limits) of the elements enable us to place these stars in different CEMP classes. The carbon abundances confirm the existence of a plateau at A(C)= 8.25 for [Fe/H] ≥ -3.4. The most metal-poor stars ([Fe/H] < -3.4) have significantly lower carbon abundances, suggesting a lower plateau at A(C) ≈ 6.5. Detailed analyses of a larger sample of very low metallicity carbon-rich stars are required to confirm (or refute) this possible second plateau and specify the behavior of the CEMP stars at very low metallicity. Based on observations obtained with the ESO Very Large Telescope at Paranal Observatory, Chile (ID 087.D-0123(A).Table 5 is available in electronic form at http://www.aanda.org ]]> http://telbib.eso.org/detail.php?id=47854 http://telbib.eso.org/detail.php?id=47853 Instruments: VIRCAM
ProgramIDs: 179.B-2002
BibCode: 2013A&A...552A.110G

Aims: We investigate the large-scale metallicity distribution in the Galactic bulge using large spatial coverage to constrain the bulge formation scenario. Methods: We use the VISTA variables in the Via Lactea (VVV) survey data and 2MASS photometry, which cover 320 sqdeg of the Galactic bulge, to derive photometric metallicities by interpolating the (J - Ks)0 colors of individual red giant branch stars based on a set of globular cluster ridge lines. We then use this information to construct the first global metallicity map of the bulge with a resolution of 30' × 45'. Results: The metallicity map of the bulge revealed a clear vertical metallicity gradient of ~0.04 dex/deg (~0.28 dex/kpc), with metal-rich stars ([Fe/H] ~ 0) dominating the inner bulge in regions closer to the Galactic plane (|b| < 5). At larger scale heights, the mean metallicity of the bulge population becomes significantly more metal poor. Conclusions: This fits in the scenario of a boxy bulge originating from the vertical instability of the Galactic bar, formed early via secular evolution of a two-component stellar disk. Older metal-poor stars dominate at higher scale heights due to the non-mixed orbits of originally hotter thick disk stars. Based on observations taken within the ESO VISTA Public Survey VVV, Program ID 179.B-2002. ]]> http://telbib.eso.org/detail.php?id=47853 http://telbib.eso.org/detail.php?id=47850 Instruments: UVES
ProgramIDs: 082.C-0218
BibCode: 2013MNRAS.431.1005D

We explore the possible connection between the open cluster IC 2391 and the unbound Argus association identified by the search for associations containing young stars survey. In addition to common kinematics and ages between these two systems, here we explore their chemical abundance patterns to confirm if the two substructures shared a common origin. We carry out a homogenous high-resolution elemental abundance study of eight confirmed members of IC 2391 as well as six members of the Argus association using UVES spectra. We derive spectroscopic stellar parameters and abundances for Fe, Na, Mg, Al, Si, Ca, Ti, Cr, Ni and Ba. All stars in the open cluster and Argus association were found to share similar abundances with the scatter well within the uncertainties, where [Fe/H] = -0.04 ± 0.03 for cluster stars and [Fe/H] = -0.06 ± 0.05 for Argus stars. Effects of overionization/excitation were seen for stars cooler than roughly 5200 K as previously noted in the literature. Also, enhanced Ba abundances of around 0.6 dex were observed in both systems. The common ages, kinematics and chemical abundances strongly support the fact that the Argus association stars originated from the open cluster IC 2391. Simple modelling of this system finds this dissolution to be consistent with two-body interactions. ]]> http://telbib.eso.org/detail.php?id=47850 http://telbib.eso.org/detail.php?id=47848 Instruments: FORS2
ProgramIDs: 384.D-0386, 386.D-0585
BibCode: 2013A&A...552A.127D

Context. PSR J1048-5832 is a young radio-pulsar that has recently been detected in γ-rays with Fermi, and also in X-rays with Chandra and XMM-Newton. It powers a compact pulsar wind nebula visible in X-rays and is in many ways similar to the Vela pulsar. Aims: We present deep optical observations made with the ESO Very Large Telescope to search for optical counterparts of the pulsar and its nebula and to explore their multi-wavelength emission properties. Methods: The data were obtained in the V and R bands and were compared with archival data in other spectral domains. Results: We do not detect the pulsar in the optical and derive informative upper limits of R ≳ 28.m1 and V ≳ 28.m4 for its brightness. Using a red-clump star method, we estimate an interstellar extinction towards the pulsar of AV ≈ 2 mag, which is consistent with the absorbing column density derived from X-rays. The respective distance agrees with the dispersion measure distance. We reanalysed the Chandra X-ray data and compared the dereddened upper limits with the unabsorbed X-ray spectrum of the pulsar. We find that regarding its optical-X-ray spectral properties this γ-ray pulsar is not distinct from other pulsars detected in both ranges. However, like the Vela pulsar, it is very inefficient in the optical and X-rays. Among a dozen optical sources overlapping with the pulsar X-ray nebula we find one with V ≈ 26.m9 and R ≈ 26.m3, whose colour is slightly bluer than that of the field stars and is consistent with the peculiar colours typical for pulsar nebula features. It positionally coincides with a relatively bright feature of the pulsar X-ray nebula, resembling the Crab wisp and is located in ~2 from the pulsar. We suggest this source as a counterpart candidate to the feature. Conclusions: Based on the substantial interstellar extinction towards the pulsar and its optical inefficiency, additional optical studies should be carried out at longer wavelengths. Based on observations made with ESO telescope at the Paranal Observatory under Programs 384.D-0386(A) and 386.D-0585(A).FITS files for the fully processed images are available at the CDS via anonymous ftp to ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/552/A127 ]]> http://telbib.eso.org/detail.php?id=47848 http://telbib.eso.org/detail.php?id=47840 Instruments: FLAMES-GIRAFFE
ProgramIDs: 085.D-0698
BibCode: 2013ApJ...768...27M

M 22 is an anomalous globular cluster that hosts two groups of stars with different metallicity and s-element abundance. The star-to-star light-element variations in both groups, with the presence of individual Na-O and C-N anticorrelations, demonstrates that this Milky Way satellite has experienced a complex star formation history. We have analyzed FLAMES/UVES spectra for seven stars covering a small color interval on the reddest horizontal branch (HB) portion of this cluster and investigated possible relations between the chemical composition of a star and its location along the HB. Our chemical abundance analysis takes into account effects introduced by deviations from the local thermodynamic equilibrium (NLTE effects), which are significant for the measured spectral lines in the atmospheric parameters range spanned by our stars. We find that all the analyzed stars are barium-poor and sodium-poor, thus supporting the idea that the position of a star along the HB is strictly related to the chemical composition, and that the HB morphology is influenced by the presence of different stellar populations. Based on data collected at the European Southern Observatory with the FLAMES/UVES spectrograph under the program 085.D-0698A. ]]> http://telbib.eso.org/detail.php?id=47840 http://telbib.eso.org/detail.php?id=47835 Instruments: ALMA_Bands
ProgramIDs: 2011.0.00275.S
BibCode: 2013A&A...552L..10S

We report on ALMA observations of continuum and molecular line emission with 0."4 resolution towards the high-mass star-forming region G35.20-0.74 N. Two dense cores are detected in typical hot-core tracers (e.g., CH3CN) that reveal velocity gradients. In one of these cores, the velocity field can be fitted with an almost edge-on Keplerian disk rotating about a central mass of ~18 M&sun;. This finding is consistent with the results of a recent study of the CO first overtone bandhead emission at 2.3 μm towards G35.20-0.74 N. The disk radius and mass are ≳2500 au and ~3 M&sun;. To reconcile the observed bolometric luminosity (~3 × 104 L&sun;) with the estimated stellar mass of 18 M&sun;, we propose that the latter is the total mass of a binary system. ]]> http://telbib.eso.org/detail.php?id=47835 http://telbib.eso.org/detail.php?id=47834 Instruments: HAWK-I
ProgramIDs: 286.D-5005
BibCode: 2013ApJ...767..162C

We present the Pan-STARRS1 discovery of PS1-10afx, a unique hydrogen-deficient superluminous supernova (SLSN) at redshift z = 1.388. The light curve peaked at z P1 = 21.7 mag, making PS1-10afx comparable to the most luminous known SNe, with Mu = –22.3 mag. Our extensive optical and near-infrared observations indicate that the bolometric light curve of PS1-10afx rose on the unusually fast timescale of ~12 days to the extraordinary peak luminosity of 4.1 × 1044 erg s–1 (M bol = –22.8 mag) and subsequently faded rapidly. Equally important, the spectral energy distribution is unusually red for an SLSN, with a color temperature of ~6800 K near maximum light, in contrast to previous hydrogen-poor SLSNe, which are bright in the ultraviolet (UV). The spectra more closely resemble those of a normal SN Ic than any known SLSN, with a photospheric velocity of ~11, 000 km s–1 and evidence for line blanketing in the rest-frame UV. Despite the fast rise, these parameters imply a very large emitting radius (gsim 5 × 1015 cm). We demonstrate that no existing theoretical model can satisfactorily explain this combination of properties: (1) a nickel-powered light curve cannot match the combination of high peak luminosity with the fast timescale; (2) models powered by the spindown energy of a rapidly rotating magnetar predict significantly hotter and faster ejecta; and (3) models invoking shock breakout through a dense circumstellar medium cannot explain the observed spectra or color evolution. The host galaxy is well detected in pre-explosion imaging with a luminosity near L*, a star formation rate of ~15 M &sun; yr–1, and is fairly massive (~2 × 1010 M &sun;), with a stellar population age of ~108 yr, also in contrast to the young dwarf hosts of known hydrogen-poor SLSNe. PS1-10afx is distinct from known examples of SLSNe in its spectra, colors, light-curve shape, and host galaxy properties, suggesting that it resulted from a different channel than other hydrogen-poor SLSNe. ]]> http://telbib.eso.org/detail.php?id=47834 http://telbib.eso.org/detail.php?id=47831 Instruments: NACO
ProgramIDs: 072.D-0433, 073.D-0406
BibCode: 2013MNRAS.431..554R

Super star clusters (SSCs) are typically found in interacting galaxies and trace an extreme form of star formation. We present a K-band study of SSC candidates in a sample of local luminous infrared galaxies (LIRGs) using two adaptive optics instruments: the Very Large Telescope's Nasmyth Adaptive Optics System-COude Near Infrared CAmera (NACO) and Gemini's ALTtitude conjugate Adaptive optics for the InfraRed (ALTAIR)/Near InfraRed Imager and Spectrometer (NIRI). In addition to facilitating SSC detections in obscured environments, this work introduces SSC studies in hosts with higher star-formation rates (SFRs) than most previous studies. We find that the luminosity functions (LFs) of the clusters are reasonably well-fitted by a single power law with values of the index α ranging between 1.5 and 2.4 with an average value of α ≈ 1.9. This value appears to be less steep than the average α ≈ 2.2 in normal spiral galaxies. Due to the host galaxy distances involved (median DL ˜ 70 Mpc), blending effects have to be taken into account and are investigated using Monte Carlo simulations of blending effects for LFs and a photometric SSC analysis of the well-studied Antenna system, which is artificially redshifted to the distance of our sample. While blending tends to flatten LFs, our analyses show that Δα is less than ˜0.1 in our sample. The simulations also show that in the luminosity range MK < -13 considered in this work, the extracted SSC luminosities are generally dominated by a single dominant star cluster rather than several knots of star formation. We present resolution- and distance-dependent SSC surface-density confusion limits and show how blending rates and aperture sizes affect the LFs. The smallest possible apertures should be used in crowded regions. ]]> http://telbib.eso.org/detail.php?id=47831 http://telbib.eso.org/detail.php?id=47828 Instruments: EFOSC2_NTT
ProgramIDs: 088.C-0204
BibCode: 2013MNRAS.431..966T

We present photometric observations of two transits in the WASP-50 planetary system, obtained using the ESO New Technology Telescope and the defocused-photometry technique. The rms scatters for the two data sets are 258 and 211 ppm with a cadence of 170-200 s, setting a new record for ground-based photometric observations of a point source. The data were modelled and fitted using the PRISM and GEMC codes, and the physical properties of the system calculated. We find the mass and radius of the hot star to be 0.861 ± 0.057 M&sun; and 0.855 ± 0.019 R&sun;, respectively. For the planet we find a mass of 1.437 ± 0.068 MJup, a radius of 1.138 ± 0.026 RJup and a density of 0.911 ± 0.033 ρJup. These values are consistent with but more precise than those found in the literature. We also obtain a new orbital ephemeris for the system: T0 = BJD/TDB 245 5558.612 37 (20) + 1.955 0938(13) × E. ]]> http://telbib.eso.org/detail.php?id=47828 http://telbib.eso.org/detail.php?id=47826 Instruments: CRIRES
ProgramIDs: 186.C-0289
BibCode: 2013ApJ...767...27B

In this paper, we present ground-based high-resolution spectroscopy of 51 Pegasi using CRIRES at the Very Large Telescope. The system was observed for 3 × 5 hr at 2.3 μm at a spectral resolution of R = 100,000, targeting potential signatures from carbon monoxide, water vapor, and methane in the planet's dayside spectrum. In the first 2 × 5 hr of data, we find a combined signal from carbon monoxide and water in absorption at a formal 5.9σ confidence level, indicating a non-inverted atmosphere. We derive a planet mass of M P = (0.46 ± 0.02)M Jup and an orbital inclination i between 79.°6 and 82.°2, with the upper limit set by the non-detection of the planet transit in previous photometric monitoring. However, there is no trace of the signal in the final five hours of data. A statistical analysis indicates that the signal from the first two nights is robust, but we find no compelling explanation for its absence in the final night. The latter suffers from stronger noise residuals and greater instrumental instability than the first two nights, but these cannot fully account for the missing signal. It is possible that the integrated dayside emission from 51 Peg b is instead strongly affected by weather. However, more data are required before we can claim any time variability in the planet's atmosphere. ]]> http://telbib.eso.org/detail.php?id=47826 http://telbib.eso.org/detail.php?id=47824 Instruments: CRIRES
ProgramIDs: 088.C-0092, 289.C-5014
BibCode: 2013ApJ...766..100P

We observed Comet 29P/Schwassmann-Wachmann 1 (hereafter, 29P) in 2012 February and May with CRIRES/VLT and NIRSPEC/Keck-II, when the comet was at 6.26 AU from the Sun and about 5.50 AU from Earth. With CRIRES, we detected five CO emission lines on several nights in each epoch, confirming the ubiquitous content and release of carbon monoxide from the nucleus. This is the first simultaneous detection of multiple lines from any (neutral) gaseous species in comet 29P at infrared wavelengths. It is also the first extraction of a rotational temperature based on the intensities of simultaneously measured spectral lines in 29P, and the retrieved rotational temperature is the lowest obtained in our infrared survey to date. We present the retrieved production rates (~3 × 1028 molecules s-1) and remarkably low (~5 K) rotational temperatures for CO, and compare them with results from previous observations at radio wavelengths. Along with CO, we pursued detections of other volatiles, namely H2O, C2H6, C2H2, CH4, HCN, NH3, and CH3OH. Although they were not detected, we present sensitive upper limits. These results establish a new record for detections by infrared spectroscopy of parent volatiles in comets at large heliocentric distances. Until now considered to be a somewhat impossible task with IR ground-based facilities, these discoveries demonstrate new opportunities for targeting volatile species in distant comets. Based on observations obtained at the European Southern Observatory at Cerro Paranal, Chile, under programs 088.C-0092 and 289.C-5014; and the Keck Observatory on Mauna Kea, Hawaii, under program C252ANS. ]]> http://telbib.eso.org/detail.php?id=47824 http://telbib.eso.org/detail.php?id=47812 Instruments: FLAMES-GIRAFFE
ProgramIDs: 085.D-0928, 086.D-0573
BibCode: 2013A&A...552A..49L

Context. The formation of supermassive black holes at high redshift still remains a puzzle to astronomers. No accretion mechanism can explain the fast growth from a stellar mass black hole to several billion solar masses in less than one Gyr. The growth of supermassive black holes becomes reasonable only when starting from a massive seed black hole with mass on the order of 102-105 M&sun;. Intermediate-mass black holes are therefore an important field of research. Especially the possibility of finding them in the centers of globular clusters has recently drawn attention. Searching for kinematic signatures of a dark mass in the centers of globular clusters provides a unique test for the existence of intermediate-mass black holes and will shed light on the process of black-hole formation and cluster evolution. Aims: We are investigating six galactic globular clusters for the presence of an intermediate-mass black hole at their centers. Based on their kinematic and photometric properties, we selected the globular clusters NGC 1851, NGC 1904 (M 79), NGC 5694, NGC 5824, NGC 6093 (M 80), and NGC 6266 (M 62). Methods: We used integral field spectroscopy to obtain the central velocity-dispersion profile of each cluster. In addition we completed these profiles with outer kinematic points from previous measurements for the clusters NGC 1851, NGC 1094, NGC 5824, and NGC 6093. We also computed the cluster photometric center and the surface brightness profile using HST data. After combining these datasets we compared them to analytic Jeans models. We used varying M/LV profiles for clusters with enough data points in order to reproduce their kinematic profiles in an optimal way. Finally, we varried the mass of the central black hole and tested whether the cluster is better fitted with or without an intermediate-mass black hole. Results: We present the statistical significance, including upper limits, of the black-hole mass for each cluster. NGC 1904 and NGC 6266 provide the highest significance for a black hole. Jeans models in combination with a M/LV profile obtained from N-body simulations (in the case of NGC 6266) predict a central black hole of M• = (3 ± 1) × 103 M&sun; for NGC 1904 and M• = (2 ± 1) × 103 M&sun; for NGC 6266. Furthermore, we discuss the possible influence of dark remnants and mass segregation at the center of the cluster on the detection of an IMBH. Based on observations collected at the European Organization for Astronomical Research in the Southern Hemisphere, Chile (085.D-0928, 086.D-0573).Tables 3 and 6 are available in electronic form at http://www.aanda.orgReduced datacubes are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr(130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/552/A49 ]]> http://telbib.eso.org/detail.php?id=47812 http://telbib.eso.org/detail.php?id=47810 Instruments: UVES
ProgramIDs: 68.D-0254
BibCode: 2013A&A...552A..28N

Context. Chemically peculiar A-type (Ap) stars are a subgroup of the CP2 stars that exhibit anomalous overabundances of numerous elements, e.g. Fe, Cr, Sr, and rare earth elements. The pulsating subgroup of Ap stars, the roAp stars, present ideal laboratories to observe and model pulsational signatures, as well as the interplay of the pulsations with strong magnetic fields and vertical abundance gradients. Aims: Based on high-resolution spectroscopic observations and observed stellar energy distributions, we construct a self-consistent model atmosphere for the roAp star 10 Aquilae (HD 176232). It accounts for modulations of the temperature-pressure structure caused by vertical abundance gradients. We demonstrate that such an analysis can be used to determine precisely the fundamental atmospheric parameters required for pulsation modelling. Methods: Average abundances were derived for 56 species. For Mg, Si, Ca, Cr, Fe, Co, Sr, Pr, and Nd, vertical stratification profiles were empirically derived using the DDAFit minimisation routine together with the magnetic spectrum synthesis codeSynthmag. Model atmospheres were computed with the LLmodels code, which accounts for the individual abundances and stratification of chemical elements. Results: For the final model atmosphere, Teff = 7550 K and log (g) = 3.8 were adopted. While Mg, Si, Co, and Cr exhibit steep abundance gradients, Ca, Fe, and Sr showed much wider abundance gradients between logτ5000 = -1.5 and 0.5. Elements Mg and Co were found to be the least stratified, while Ca and Sr showed strong depth variations in abundance of up to ≈ 6 dex. Table 4 and Figs. 10-12 are available in electronic form at http://www.aanda.org ]]> http://telbib.eso.org/detail.php?id=47810 http://telbib.eso.org/detail.php?id=47803 Instruments: EFOSC2_3.6, EMMI
ProgramIDs: 080.A-0516
BibCode: 2013ApJ...767...57F

We describe observed properties of the Type Iax class of supernovae (SNe Iax), consisting of SNe observationally similar to its prototypical member, SN 2002cx. The class currently has 25 members, and we present optical photometry and/or optical spectroscopy for most of them. SNe Iax are spectroscopically similar to SNe Ia, but have lower maximum-light velocities (2000 <~ |v| <~ 8000 km s–1), typically lower peak magnitudes (–14.2 >= M V, peak >~ –18.9 mag), and most have hot photospheres. Relative to SNe Ia, SNe Iax have low luminosities for their light-curve shape. There is a correlation between luminosity and light-curve shape, similar to that of SNe Ia, but offset from that of SNe Ia and with larger scatter. Despite a host-galaxy morphology distribution that is highly skewed to late-type galaxies without any SNe Iax discovered in elliptical galaxies, there are several indications that the progenitor stars are white dwarfs (WDs): evidence of C/O burning in their maximum-light spectra, low (typically ~0.5 M &sun;SUB) ejecta masses, strong Fe lines in their late-time spectra, a lack of X-ray detections, and deep limits on massive stars and star formation at the SN sites. However, two SNe Iax show strong He lines in their spectra. The progenitor system and explosion model that best fits all of the data is a binary system of a C/O WD that accretes matter from a He star and has a deflagration. At least some of the time, this explosion will not disrupt the WD. The small number of SNe in this class prohibit a detailed analysis of the homogeneity and heterogeneity of the entire class. We estimate that in a given volume there are 31^{+17}_{-13} SNe Iax for every 100 SNe Ia, and for every 1 M &sun; of iron generated by SNe Ia at z = 0, SNe Iax generate ~0.036 M &sun;. Being the largest class of peculiar SNe, thousands of SNe Iax will be discovered by LSST. Future detailed observations of SNe Iax should further our understanding of both their progenitor systems and explosions as well as those of SNe Ia. This paper is dedicated to the memory of our friend and colleague, Dr. Weidong Li, a pioneer in the identification and detailed study of this class of objects. ]]> http://telbib.eso.org/detail.php?id=47803 http://telbib.eso.org/detail.php?id=47800 Instruments: FORS2
ProgramIDs: 080.A-0610
BibCode: 2013A&A...552A..80M

We present VLT spectroscopic observations of seven newly discovered galaxy groups between 0.3 < z < 0.7. The groups were selected from the Strong Lensing Legacy Survey (SL2S), a survey that consists of a systematic search for strong lensing systems in the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS). We give details about the target selection, spectroscopic observations, and data reduction for the first release of confirmed SL2S groups. The dynamical analysis of the systems reveals that they are gravitationally bound structures, with at least 4 confirmed members and velocity dispersions between 300 and 800 km s-1. Their virial masses are between 1013 and 1014 M&sun;, so they can be classified as groups or low mass clusters. Most of the systems are isolated groups, except two of them that show evidence of an ongoing merger of two substructures. We find that weak lensing estimates of the group velocity dispersions are 50% greater than estimates based upon the radial velocities of its members, and conclude that the dynamics of baryonic matter is a good tracer of the total mass content in galaxy groups. Based on observations collected at the European Southern Observatory, Paranal, Chile (Program P80.A-0610B); based on observations obtained with MegaPrime/MegaCam, a joint project of CFHT and CEA/DAPNIA, at the Canada-France-Hawaii Telescope (CFHT), which is operated by the National Research Council (NRC) of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii. This work is based in part on data products produced at TERAPIX and the Canadian Astronomy Data Centre as part of the Canada-France-Hawaii Telescope Legacy Survey, a collaborative project of NRC and CNRS.Appendices are available in electronic form at http://www.aanda.orgReduced spectra are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/552/A80 ]]> http://telbib.eso.org/detail.php?id=47800 http://telbib.eso.org/detail.php?id=47797 Instruments: EFOSC2_NTT, FORS2
ProgramIDs: 184.D-1140, 089.D-0032
BibCode: 2013ApJ...767...71M

We present X-ray, UV/optical, and radio observations of the stripped-envelope, core-collapse supernova (SN) 2011ei, one of the least luminous SNe IIb or Ib observed to date. Our observations begin with a discovery within ~1 day of explosion and span several months afterward. Early optical spectra exhibit broad, Type II-like hydrogen Balmer profiles that subside rapidly and are replaced by Type Ib-like He-rich features on a timescale of one week. High-cadence monitoring of this transition suggests absorption attributable to a high-velocity (gsim 12, 000 km s–1) H-rich shell, which is likely present in many Type Ib events. Radio observations imply a shock velocity of v ≈ 0.13 c and a progenitor star average mass-loss rate of \dot{M}≈ 1.4 × 10^{-5} M_{&sun;} yr^{-1} (assuming wind velocity vw = 103 km s–1). This is consistent with independent constraints from deep X-ray observations with Swift-XRT and Chandra. Overall, the multi-wavelength properties of SN 2011ei are consistent with the explosion of a lower-mass (3-4 M &sun;), compact (R * <~ 1 × 1011 cm), He-core star. The star retained a thin hydrogen envelope at the time of explosion, and was embedded in an inhomogeneous circumstellar wind suggestive of modest episodic mass loss. We conclude that SN 2011ei's rapid spectral metamorphosis is indicative of time-dependent classifications that bias estimates of the relative explosion rates for Type IIb and Ib objects, and that important information about a progenitor star's evolutionary state and mass loss immediately prior to SN explosion can be inferred from timely multi-wavelength observations. ]]> http://telbib.eso.org/detail.php?id=47797 http://telbib.eso.org/detail.php?id=47783 Instruments: X-SHOOTER
ProgramIDs: 086.A-0968
BibCode: 2013MNRAS.430.3314B

We present spectroscopic observations with VLT/XSHOOTER and Subaru/MOIRCS of a relatively bright Y-band drop-out galaxy in the Hubble Ultra Deep Field (HUDF), first selected by Bunker et al., McLure et al. and Bouwens et al. to be a likely z ≈ 8-9 galaxy on the basis of its colours in the Hubble Space Telescope (HST) Advanced Camera for Surveys and Wide Field Camera 3 images. This galaxy, HUDF.YD3 (also known as UDFy-38135539), has been targetted for VLT/SINFONI integral field spectroscopy by Lehnert et al., who published a candidate Lyman α emission line at z = 8.55 from this source. In our independent spectroscopy using two different infrared spectrographs (5 h with VLT/XSHOOTER and 11 h with Subaru/MOIRCS), we are unable to reproduce this line. We do not detect any emission line at the spectral and spatial location reported in Lehnert et al., despite the expected signal in our combined MOIRCS and XSHOOTER data being 5σ. The line emission also seems to be ruled out by the faintness of this object in recently extremely deep F105W (Y band) HST/WFC 3 imaging from HUDF12; the line would fall within this filter and such a galaxy should have been detected at YAB = 28.6 mag (˜20σ) rather than the marginal YAB ≈ 30 mag observed in the Y-band image, >3 times fainter than would be expected if the emission line was real. Hence, it appears highly unlikely that the reported Lyman α line emission at z > 8 is real, meaning that the highest redshift sources for which Lyman α emission has been seen are at z = 6.9-7.2. It is conceivable that Lyman α does not escape galaxies at higher redshifts, where the Gunn-Peterson absorption renders the Universe optically thick to this line. However, deeper spectroscopy on a larger sample of candidate z > 7 galaxies will be needed to test this. ]]> http://telbib.eso.org/detail.php?id=47783 http://telbib.eso.org/detail.php?id=47782 Instruments: WFI
ProgramIDs: 164.O-0561, 077.C-0188
BibCode: 2013MNRAS.430.3350Y

Relative proper motions (PMs) and cluster membership probabilities (Pμ) were derived for ˜2500 stars in the field of the open star cluster NGC 3766. The cluster was observed in the B and V broad-band filters at two epochs separated by ˜6 yr using a wide-field imager mounted on the WFI@ESO 2.2-m telescope. All CCD frames were reduced using the astrometric techniques described by Anderson et al. The PM rms error for stars brighter than V ˜ 15 mag is 2.0 mas yr-1, but it gradually increases up to ˜4 mas yr-1 at V ˜ 20 mag. Using PM data, membership probabilities were derived for the stars in the region of the cluster. They indicate that one Ap and three Be stars are members of the cluster. A reddening of E(B - V) = 0.22 ± 0.05 mag, a distance of 2.5 ± 0.5 kpc and an age of ˜20 Myr were derived using stars with Pμ > 70 per cent. A mass function slope of x = 1.60 ± 0.10 was derived for the cluster, and the cluster was found to be dynamically relaxed. Finally, we provide positions, calibrated B and V magnitudes, relative PMs and membership probabilities for the stars in the field of NGC 3766. We have produced a catalogue that is electronically available to the astronomical community. ]]> http://telbib.eso.org/detail.php?id=47782 http://telbib.eso.org/detail.php?id=47781 Instruments: FLAMES-GIRAFFE
ProgramIDs: 078.C-0247
BibCode: 2013MNRAS.430.3406T

Photoevaporating protoplanetary discs (proplyds) in the vicinity of hot massive stars, such as those found in Orion, are important objects of study for the fields of star formation, early disc evolution, planetary formation and H II region astrophysics. Their element abundances are largely unknown, unlike those of the main-sequence stars or the host Orion nebula. We present a spectroscopic analysis of the Orion proplyd HST 10, based on integral field observations with the Very Large Telescope/FLAMES fibre array with 0.31 × 0.31 arcsec2 spatial pixels. The proplyd and its vicinity are imaged in a variety of emission lines across a 6.8 × 4.3 arcsec2 area. The reddening, electron density and temperature are mapped out from various line diagnostics. The abundances of helium, and eight heavy elements, are measured relative to hydrogen using the direct method based on the [O III] electron temperature. The abundance ratios of O/H and S/H are derived without resort to ionization correction factors. We construct dynamic photoevaporation models of HST 10 with the CLOUDY microphysics code that validate the oxygen and sulphur abundances. With the exception of [O I] λ6300 and [S II] λ4069, the model fit is satisfactory for all spectral lines arising from the proplyd. The models show that the classic ionization correction factor for neon significantly underestimates (0.4 dex) this element's abundance in the low ionization conditions of HST 10. Apart from iron, whose gas-phase abundance is ˜0.3 dex lower than in the local Orion nebula, most other elements in the proplyd do not show substantially different gas-phase abundances from the nebula. The abundances of carbon, oxygen and neon in HST 10 are practically the same as those in B-type stars in Orion. ]]> http://telbib.eso.org/detail.php?id=47781 http://telbib.eso.org/detail.php?id=47777 Instruments: EFOSC2_NTT, FORS2, SOFI, X-SHOOTER
ProgramIDs: 184.D-1140, 087.D-0693, 089.D-0325, 083.D-0131, 083.D-0970
BibCode: 2013ApJ...767....1P

We report the results of a three-year-long dedicated monitoring campaign of a restless luminous blue variable (LBV) in NGC 7259. The object, named SN 2009ip, was observed photometrically and spectroscopically in the optical and near-infrared domains. We monitored a number of erupting episodes in the past few years, and increased the density of our observations during eruptive episodes. In this paper, we present the full historical data set from 2009 to 2012 with multi-wavelength dense coverage of the two high-luminosity events between 2012 August and September. We construct bolometric light curves and measure the total luminosities of these eruptive or explosive events. We label them the 2012a event (lasting ~50 days) with a peak of 3 × 1041 erg s–1, and the 2012b event (14 day rise time, still ongoing) with a peak of 8 × 1042 erg s–1. The latter event reached an absolute R-band magnitude of about –18, comparable to that of a core-collapse supernova (SN). Our historical monitoring has detected high-velocity spectral features (~13,000 km s–1) in 2011 September, one year before the current SN-like event. This implies that the detection of such high-velocity outflows cannot, conclusively, point to a core-collapse SN origin. We suggest that the initial peak in the 2012a event was unlikely to be due to a faint core-collapse SN. We propose that the high intrinsic luminosity of the latest peak, the variability history of SN 2009ip, and the detection of broad spectral lines indicative of high-velocity ejecta are consistent with a pulsational pair-instability event, and that the star may have survived the last outburst. The question of the survival of the LBV progenitor star and its future fate remain open issues, only to be answered with future monitoring of this historically unique explosion. ]]> http://telbib.eso.org/detail.php?id=47777 http://telbib.eso.org/detail.php?id=47776 Instruments: X-SHOOTER
ProgramIDs: 088.B-0015
BibCode: 2013ApJ...767....3D

We present a re-appraisal of the temperatures of red supergiants (RSGs) using their optical and near-infrared spectral energy distributions (SEDs). We have obtained data of a sample of RSGs in the Magellanic Clouds using VLT+XSHOOTER, and we fit MARCS model atmospheres to different regions of the spectra, deriving effective temperatures for each star from (1) the TiO bands, (2) line-free continuum regions of the SEDs, and (3) the integrated fluxes. We show that the temperatures derived from fits to the TiO bands are systematically lower than the other two methods by several hundred kelvin. The TiO fits also dramatically overpredict the flux in the near-IR, and imply extinctions which are anomalously low compared to neighboring stars. In contrast, the SED temperatures provide good fits to the fluxes at all wavelengths other than the TiO bands, are in agreement with the temperatures from the flux integration method, and imply extinctions consistent with nearby stars. After considering a number of ways to reconcile this discrepancy, we conclude that three-dimensional effects (i.e., granulation) are the most likely cause, as they affect the temperature structure in the upper layers where the TiO lines form. The continuum, however, which forms at much deeper layers, is apparently more robust to such effects. We therefore conclude that RSG temperatures are much warmer than previously thought. We discuss the implications of this result for stellar evolution and supernova progenitors, and provide relations to determine the bolometric luminosities of RSGs from single-band photometry. ]]> http://telbib.eso.org/detail.php?id=47776 http://telbib.eso.org/detail.php?id=47775 Instruments: FEROS2.2
ProgramIDs: 084.C-1008
BibCode: 2013ApJ...767...32A

With observations of the EP Cru system, we continue our series of measurements of spin-orbit angles in eclipsing binary star systems, the BANANA project (Binaries Are Not Always Neatly Aligned). We find a close alignment between the sky projections of the rotational and orbital angular momentum vectors for both stars (βp = –1.°8 ± 1.°6 and |βs| < 17°). We also derive precise absolute dimensions and stellar ages for this system. The EP Cru and DI Her systems provide an interesting comparison: they have similar stellar types and orbital properties, but DI Her is younger and has major spin-orbit misalignments, raising the question of whether EP Cru also had a large misalignment at an earlier phase of evolution. We show that tidal dissipation is an unlikely explanation for the good alignment observed today, because realignment happens on the same timescale as spin-orbit synchronization, and the stars in EP Cru are far from synchronization (they are spinning nine times too quickly). Therefore it seems that some binaries form with aligned axes, while other superficially similar binaries are formed with misaligned axes. Based on observations made with ESOs 2.2 m Telescopes at the La Silla Paranal Observatory under program ID 084.C-1008 (12.5%) and under MPIA guaranteed time (87.5%). ]]> http://telbib.eso.org/detail.php?id=47775 http://telbib.eso.org/detail.php?id=47772 Instruments: SOFI
ProgramIDs: 089.C-0854
BibCode: 2013MNRAS.430.1784L

We present new z- and H-band photometry and proper motion measurements for the five candidate very-low-mass T-type objects we recently proposed to be members of the nearest OB association with the Sun, Upper Scorpius (USco). These new data fail to corroborate our prior conclusions regarding their spectral types and affiliation with the USco population. We conclude that we may be in presence of a turnover in the mass function of USco taking place below 10-4 MJup, depending on the age assigned to USco and the models used. ]]> http://telbib.eso.org/detail.php?id=47772