Messenger No. 146 (December 2011)

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Telescopes and Instrumentation

2-7 (PDF)
M. Capaccioli, P. Schipani
The VLT Survey Telescope Opens to the Sky: History of a Commissioning

ADS BibCode:
2011Msngr.146....2C
Section:
Telescopes and Instrumentation
Author(s)/Affiliation(s):
Capaccioli, M.; Schipani, P.
AA(Department of Physical Sciences, University Federico II, Naples, Italy) AB(INAF–Capodimonte Astronomical Observatory, Naples, Italy)
Abstract:
The VLT Survey Telescope (VST) is now ready to undertake its mission. After a long gestation, the telescope has revealed its power, providing image quality and resolution beyond expectation. This achievement has been made possible by a motivated team of scientists and engineers who have brought the VST to its current state of readiness for survey science. This paper briefly reviews the latest stages of the project and the characteristics of the VST, and lists the scientific programmes for the observing time guaranteed by ESO to the Italian community in return for the procurement of the telescope.
References:
Capaccioli, M., Mancini, D. & Sedmak, G. 2003, Mem. SAIt, 74, 450; Capaccioli, M., Mancini, D. & Sedmak, G. 2005, The Messenger, 120, 10
8-11 (PDF)
K. Kuijken
OmegaCAM: ESO’s Newest Imager

ADS BibCode:
2011Msngr.146....8K
Section:
Telescopes and Instrumentation
Author(s)/Affiliation(s):
Kuijken, K.
AA(Leiden Observatory, the Netherlands)
Abstract:
OmegaCAM, the 300-megapixel wide-field optical camera on the new VLT Survey Telescope (VST), was commissioned between March and August of this year. This new capability in ESO’s arsenal takes images of 1 degree by 1 degree patches of the sky, at 0.2 arcseconds per pixel resolution and of image quality well-matched to the natural seeing on Paranal. The commissioning and OmegaCAM’s scientific niche as a high image quality, ultra-violet- sensitive wide-field survey instrument are briefly discussed.
References:
Arnaboldi, M. et al. 2007, The Messenger, 127, 28; Filippi, G. 2010, The Messenger, 141, 2; Kuijken, K. et al. 2002, The Messenger, 110,15
12-17 (PDF)
G. Zins, B. Lazareff et al.
PIONIER: A Four-telescope Instrument for the VLTI

ADS BibCode:
2011Msngr.146...12Z
Section:
Telescopes and Instrumentation
Author(s)/Affiliation(s):
Zins, G.; Lazareff, B.; Berger, J.-P.; Le Bouquin, J.-B.; Jocou, L.; Rochat, S.; Haguenauer, P.; Knudstrup, J.; Lizon, J.-L.; Millan-Gabet, R.; Traub, W.; Benisty, M.; Delboulbe, A.; Feautrier, P.; Gillier, D.; Gitton, P.; Kern, P.; Kiekebusch, M.; Labeye, P.; Maurel, D.; Magnard, Y.; Micallef, M.; Michaud, L.; Moulin, T.; Popovic, D.; Roux, A.; Ventura, N.
AA(Institut de Planétologie et d’Astrophysique de Grenoble (IPAG), OSUG, Université Joseph Fourier, Grenoble, France) AB(ESO) AC(NASA Exoplanet Science Institute, ­California Institute of Technology, ­Pasadena, USA) AD(Exoplanet Exploration Program, Jet Propulsion Laboratory, Pasadena, USA) AE(Max-Planck-Institut für Astronomie, ­Heidelberg, Germany) AF(Laboratoire d’Electronique et Technologies de l’Information (LETI), Grenoble, France)
Abstract:
PIONIER, developed by the Institut d’Astrophysique de Grenoble (IPAG) and installed at the VLT Interferometer, is a near-infrared (1.5–2.4 μm) instrument that allows the beams from four telescopes to be recombined for the first time, thus permitting high angular resolution imaging studies at an unprecedented level of sensitivity and precision. At the heart of the instrument is an integrated optics beam combiner (IOBC) that splits and recombines the four incoming signals, providing excellent compactness and stability. The IOBC has been developed by IPAG and the Laboratoire d’Electronique et Technologies de l’Information. PIONIER was successfully commissioned in October 2010, 12 months after being approved by ESO as a visitor instrument. With the baselines up to 130 metres offered by the VLTI, PIONIER can resolve structures less than 3 milliarcseconds across. The scientific motivation behind PIONIER is outlined, the instrument is described and illustrative scientific results from the first year of operation are presented.
References:
Absil, O. et al. 2009, ApJ, 704, 150; Benisty, M. et al. 2009, A&A, 498, 601; Blind, N. et al. 2011, A&A, 536, A55; Eisenhauer, F. et al. 2011, The Messenger, 143, 16; Jocou, L. et al. 2010, Proc. SPIE, Volume 7734; Hofmann, K.-H. et al. 2008, SPIE, 7013, 122; Labeye, P. et al. 2006, in Silicon Photonics, Proc. SPIE, 6125, 161; Labeye, P. 2009, PhD dissertation, INPG, http://arxiv.org/abs/0904.3030; Le Bouquin, J.-B. et al. 2011, A&A, 535, A67; Monnier, J. D. et al. 2007, Science, 317, 342
18-23 (PDF)
S. Lacour, P. Tuthill et al.
Sparse Aperture Masking on Paranal

ADS BibCode:
2011Msngr.146...18L
Section:
Telescopes and Instrumentation
Author(s)/Affiliation(s):
Lacour, S.; Tuthill, P.; Ireland, M.; Amico, P.; Girard, J.
AA(Observatoire de Paris, Meudon, France) AB(Sydney Institute for Astronomy, Sydney University, Australia) AC(Sydney Institute for Astronomy, Sydney University, Australia; Australian Astronomical Observatory, Epping, Australia) AD(ESO)
Abstract:
The new operational mode of aperture-masking interferometry was added to the CONICA camera four years ago. Over the years, the masks — pieces of metal only two centimetres wide — have opened an unprecedented observational window for the NACO instrument. In comparison to the full aperture, they deliver superior point source function calibration, rejection of atmospheric noise and robust recovery of phase information through the use of closure phases. In the resolution range from about half to several resolution elements, masking interferometry sets the benchmark for the present state of the art worldwide in delivering high fidelity imaging and direct detection of faint companions. The technique and observational applications to imaging of circumstellar discs and exoplanets are outlined.
References:
Chauvin, G. et al. 2004, A&A, 425, L29; Evans, T. et al. 2011, ApJ, 2011, in press Huelamo, N. et al. 2011, A&A, 528, L7; Kraus, A. & Ireland, M. 2011, ApJ, in press (arXiv:1110.3808) Lacour, S. et al. 2011, A&A, 532, A72; Lagrange, A.-M. et al. 2010, Science, 329, 57; Marois, C. et al. 2008, Science, 322, 1348; Monnier, J. et al. 1999, ApJ, 512, 351; Norris, B. et al. 2011, Nature, in press Olofsson, J. et al. 2011, A&A, 528, L6; Sana, H. et al. 2011, arXiv 1109.6654

Astronomical Science

25-27 (PDF)
S. P. Quanz, H. M. Schmid et al.
Resolving the Inner Regions of Circumstellar Discs with VLT/NACO Polarimetric Differential Imaging

ADS BibCode:
2011Msngr.146...25Q
Section:
Astronomical Science
Author(s)/Affiliation(s):
Quanz, S. P.; Schmid, H. M.; Birkmann, S. M.; Apai, D.; Wolf, S.; Brandner, W.; Meyer, M. R.; Henning, T.
AA(Institute for Astronomy, ETH Zurich, Switzerland) AB(ESA/ESTEC, Noordwijk, the Netherlands) AC(Department of Astronomy/Department of Planetary Sciences, University of Arizona, Tucson, USA) AD(Institute of Theoretical Physics and Astrophysics, University of Kiel, Germany) AE(Max-Planck Institute for Astronomy, Heidelberg, Germany)
Abstract:
Planets originate from circumstellar discs of gas and dust around young stars. A better knowledge of the physical and chemical conditions in these discs is necessary in order to understand the planet formation process. As most planets form in the inner few tens of astronomical units these disc regions are of particular interest. However, the overwhelming brightness of the central star makes it very challenging to image directly those disc regions. Polarimetric Differential Imaging (PDI) is a powerful technique that overcomes these challenges. Without using a coronagraph, which would block not only the central star, but also part of the interesting inner disc region, PDI allows high-contrast imaging observations at small inner working angles.
References:
Apai, D. et al. 2004, A&A, 415, 671; Benisty, M. et al. 2010, A&A, 511, 75; Beuzit, J.-L. et al. 2006, The Messenger, 125, 29; Chauvin, G. et al. 2010, A&A, 509, 52; Kalas, P. et al. 2008, Science, 322, 1345; Marois, C. et al. 2010, Nature, 468, 1080; Quanz, S. et al. 2011a, ApJ, 738, 23; Quanz, S. et al. 2011b, A&A submitted Witzel, G. et al. 2010, The Messenger, 142, 5
28-30 (PDF)
E. Caffau, P. Bonifacio et al.
X-shooter Finds an Extremely Primitive Star

ADS BibCode:
2011Msngr.146...28C
Section:
Astronomical Science
Author(s)/Affiliation(s):
Caffau, E.; Bonifacio, P.; François, P.; Sbordone, L.; Monaco, L.; Spite, M.; Spite, F.; Ludwig, H.-G.; Cayrel, R.; Zaggia, S.; Hammer, F.; Randich, S.; Molaro, P.; Hill, V.
AA(Zentrum für Astronomie der Universität Heidelberg, Landessternwarte, Heidelberg, Germany) AB(GEPI, Observatoire de Paris, CNRS, Université Paris Diderot, Meudon, France) AC(ESO) AD(Gliese Fellow) AD(Université de Picardie Jules Verne, Amiens, France) AE(INAF, Osservatorio Astronomico di Padova, Italy) AF(INAF, Osservatorio Astrofisico di Arcetri, Firenze, Italy) AG(INAF, Osservatorio Astronomico di ­Trieste, Trieste, Italy) AH(Université de Nice-Sophia Antipolis, Observatoire de la Côte d’Azur, CNRS, Laboratoire Cassiopée, Nice, France)
Abstract:
Low-mass extremely metal-poor (EMP) stars hold the fossil record of the chemical composition of the early phases of the Universe in their atmospheres. Chemical analysis of such objects provides important constraints on these early phases. EMP stars are rather rare objects: to dig them out, large amounts of data have to be considered. We have analysed stars from the Sloan Digital Sky Survey using an automatic procedure and selected a sample of good candidate EMP stars, which we observed with the spectrographs X-shooter and UVES. We could confirm the low metallicity of our sample of stars, and we succeeded in finding a record metal-poor star.
References:
Bromm, V. & Loeb, A. 2003, Nature, 425, 812; Caffau, E. et al. 2011a, Sol. Phys., 268, 255; Caffau, E. et al. 2011b, Nature, 477, 67; Caffau, E. et al. 2011c, A&A, 534, 4; Christlieb, N. et al. 2002, Nature, 419, 904; Clark, P. C. et al. 2011, Science, 331, 1040; Frebel, A. et al. 2005, Nature, 434, 871; Greif, T. H. et al. 2011, ApJ, 737, 75; Norris, J. E. et al. 2007, ApJ, 670, 774; Sbordone, L. et al. 2010, A&A, 522, 26; Schneider, R. et al. 2011, MNRAS, in press, arXiv1109.2900; Spite, M. & Spite, F. 1982, Nature, 297, 483; Vernet, J. et al. 2011, A&A in press, arXiv 1110.1944; York, D. G. et al. 2000, AJ, 120, 1579
31-34 (PDF)
B. Clément, J.-G. Cuby et al.
Evolution of the Observed Ly-alpha Luminosity Function from z = 6.5 to z = 7.7: Evidence for the Epoch of Re-ionisation?

ADS BibCode:
2011Msngr.146...31C
Section:
Astronomical Science
Author(s)/Affiliation(s):
Clément, B.; Cuby, J.-G.; Courbin, F.; Fontana, A.; Freudling, W.; Fynbo, J.; Gallego, J.; Hibon, P.; Kneib, J.-P.; Le Fèvre, O.; Lidman, C.; McMahon, R.; Milvang-Jensen, B.; Moller, P.; Nilsson, K. K.; Pentericci, L.; Venemans, B.; Villar, V.; Willis, J.
AA(Laboratoire d’Astrophysique de Marseille, Université Aix-Marseille & CNRS, France) AB(Steward Observatory, University of ­Arizona, Tucson, USA) AC(Laboratoire d’Astrophysique, EPFL, Observatoire de Sauverny, Switzerland) AD(INAF Osservatorio Astronomico di Roma, Monteporzio, Italy) AE(ESO) AF(Dark Cosmology Centre, Copenhagen, Denmark) AG(Departamento de Astrofísica, Facultad de CC. Física, Universidad Complutense de Madrid, Spain) AH(SESE, Arizona State University, Tempe, USA) AI(Australian Astronomical Observatory, Epping, Australia) AJ(Institute of Astronomy, Cambridge, United Kingdom) AK(Department of Physics and Astronomy, University of Victoria, Canada)
Abstract:
Probing the first billion years of the Universe is one of the last frontiers in cosmology. Ly-alpha emitters (LAEs) are galaxies that can be detected out to very high redshifts during the epoch of re-ionisation. The evolution of their luminosity function with redshift is a direct probe of the Ly-alpha transmission of the intergalactic medium (IGM), related to the amount of neutral hydrogen. We report on the results of a search for LAEs at z = 7.7 using HAWK-I at the VLT with a narrowband filter centred at 1.06 μm. We did not find any LAE candidates, which allows us to infer robust constraints on the LAE luminosity function at z = 7.7. Depending on which luminosity functions at z = 6.5 are referred to, our results may reflect a significant quenching of the IGM Ly-alpha transmission, possibly from a strong increase in the neutral hydrogen fraction between these two redshifts.
References:
Bouwens, R. J. et al. 2011, ApJ 737, 90; Casali, M. et al. 2005, The Messenger, 119, 6; Clément, B. et al. 2011, arXiv:1105.4235; Hibon, P. et al. 2010, A&A, 515, A97+ Hu, E. M. et al. 2002, ApJ, 568, L75; Hu, E. M. et al. 2010, ApJ, 725, 394; Iye, M. et al. 2006, Nature, 443, 186; Kashikawa, N. et al. 2011, ApJ, 734, 119; Komatsu, E. et al. 2011, ApJS, 192, 18; Krug, H. et al. 2011, arXiv:1106.6055; Ouchi, M. et al. 2010, ApJ, 723, 869; Tilvi, V. et al. 2010, ApJ, 721, 1853; Vanzella, E. et al. 2010, ApJ, 730, L35+ Yang, A. & Saslaw, W. C. 2011, ApJ, 729, 123

Astronomical News

36-37 (PDF)
M. Arnaboldi
Report on the Workshop Fornax, Virgo, Coma et al.: Stellar Systems in High Density Environments

ADS BibCode:
2011Msngr.146...36A
Section:
Astronomical News
Author(s)/Affiliation(s):
Arnaboldi, M.
AA(ESO)
Abstract:
The workshop focused on recent observational progress in the understanding of stellar systems in the nearby clusters Fornax, Virgo, Coma et al. and provided a forum for comparing the results from theory and observations on galaxy evolution in high density environments at redshift zero.
References:
Richter, O.-G. & Binggeli, B. (eds) 1985, ESO Workshop on the Virgo Cluster of Galaxies
38-41 (PDF)
A. Calamida, A. Verma et al.
Report on the Workshop Feeding the Giants: ELTs in the Era of Surveys

ADS BibCode:
2011Msngr.146...38C
Section:
Astronomical News
Author(s)/Affiliation(s):
Calamida, A.; Verma, A.; Hook, I.; Liske, J.; Kissler-Patig, M.
AA(INAF, Osservatorio Astronomico di Roma, Monteporzio, Italy) AB(Department of Physics, University of Oxford, United Kingdom) AC(ESO)
Abstract:
Over the next decade, an incredible wealth of data will become available through many ongoing and forthcoming survey facilities. At the same time, the three Extremely Large Telescope (ELT) projects (the European ELT [E-ELT], the Thirty Meter Telescope [TMT] and the Giant Magellan Telescope [GMT]) will open a new parameter space of unprecedented sensitivity and spatial resolution. Motivated by exploring synergies between these two approaches, the workshop drew together both the survey and the ELT communities to define the first strategies to maximise the success of both aspects. The workshop was jointly organised by OPTICON and the INAF Observatory of Rome, the University of Oxford and ESO, and was held on the island of Ischia, near Naples.
References:
Diolaiti, E. 2010, The Messenger, 140, 28; Marchis, F., Spencer, J. R. & Lopes, M. C. 2005, in Io after Galileo, eds. R. M. C. Lopes and J. R. Spencer, Springer, p.287; Thatte, N. 2010, The Messenger, 140, 26
41-44 (PDF)
M. Petr-Gotzens, L. Testi
Report on the ESO/MPE/MPA/ExcellenceCluster/LMU Joint Astronomy Workshop The Formation and Early Evolution of Very Low-mass Stars and Brown Dwarfs

ADS BibCode:
2011Msngr.146...41P
Section:
Astronomical News
Author(s)/Affiliation(s):
Petr-Gotzens, M.; Testi, L.
AA(ESO) AB(ESO)
Abstract:
The topics discussed at the workshop ranged from the structure and fragmentation of molecular clouds to the formation of individual very low-mass objects, their multiplicity, physical structure, mass distribution and early evolution. Each topic was introduced by two reviews on the status of our theoretical and observational understanding of the field, followed by presentations of new results and discussions. In this report we provide a brief summary of some of the areas discussed at the workshop.
44-44 (PDF)
M. West
Brazilian Teachers and Students Visit Paranal and ALMA

ADS BibCode:
2011Msngr.146...44W
Section:
Astronomical News
Author(s)/Affiliation(s):
West, M.
AA(ESO)
45-45 (PDF)
J. Liske
ESO Presence at the Astronomical Society of Brazil Annual Meeting

ADS BibCode:
2011Msngr.146...45L
Section:
Astronomical News
Author(s)/Affiliation(s):
Liske, J.
AA(ESO)
45-46 (PDF)
M. Arnaboldi, J. Retzlaff
First ESO Public Release of Data Products from the VISTA Public Surveys

ADS BibCode:
2011Msngr.146...45A
Section:
Astronomical News
Author(s)/Affiliation(s):
Arnaboldi, M.; Retzlaff, J.
AA(ESO) AB(ESO)
References:
Arnaboldi, M. et al. 2007, The Messenger, 127, 28
46-46 (PDF)
ESO
Announcement of the Workshop Astronomical Data Analysis 7th Conference

ADS BibCode:
2011Msngr.146...46.
Section:
Astronomical News
Author(s)/Affiliation(s):
ESO
AA(ESO)
47-47 (PDF)
ESO
Introduction of Calibration Selection via the ESO Science Archive Facility and Discontinuation of PI Packages

ADS BibCode:
2011Msngr.146Q..47.
Section:
Astronomical News
Author(s)/Affiliation(s):
ESO
AA(ESO)
47-47 (PDF)
ESO
Announcement of the Joint ESO/IAG/USP Workshop Circumstellar Dynamics at High Resolution

ADS BibCode:
2011Msngr.146R..47.
Section:
Astronomical News
Author(s)/Affiliation(s):
ESO
AA(ESO)
48-49 (PDF)
ESO
Fellows at ESO

ADS BibCode:
2011Msngr.146...48.
Section:
Astronomical News
Author(s)/Affiliation(s):
ESO
AA(ESO)
49-49 (PDF)
ESO
Personnel Movements

ADS BibCode:
2011Msngr.146...49.
Section:
Astronomical News
Author(s)/Affiliation(s):
ESO
AA(ESO)
50-50 (PDF)
ESO
E-ELT Project Manager and Head of the E-ELT Division

ADS BibCode:
2011Msngr.146...50.
Section:
Astronomical News
Author(s)/Affiliation(s):
ESO
AA(ESO)