Abstracts of Large Programmes and Public Spectroscopic Surveys scheduled in Period 96

This list of OPC approved Large Programmes (LPs) is updated every observing period.



Massive stars are key agents in the Universe, driving the evolution of star forming galaxies through their photons, winds and violent deaths at all redshifts. The community devotes large efforts to characterize those processes which have been identified to affect the evolution of massive stars: rotation and stellar winds. Recently, important effects of magnetic fields in massive stars are suggested by observations and by models, and spectacular objects such as gamma-ray bursts and magnetars can not be understood without their consideration. But what is their frequency and field strength distribution, their origin, and what are the evolutionary consequences of magnetic fields in massive stars? We aim at directly addressing these questions through the study of a systematically selected sample of massive OB stars of different ages, considering their spin and their hard X-ray emission. We want to measure the polarization induced in spectral lines by the Zeeman effect. Recent observations showed that FORS\,2 and HARPS are ideal instrument for this. Through (funded) parallel theory projects, we aim to clarify the role of magnetic fields in the advanced stages of massive stars, including their fate as supernova or gamma-ray burst.




The number of planets orbiting M dwarfs increases very steeply with decreasing planetary mass or radius. At small orbital separations, M dwarfs seem to host more super-Earths than FGK stars do, and their super-Earths have a high occurence rate in the habitable zone (Bonfils et al. 2012, A\&A in press.; Howard et al. 2012, ApJS 201, 15). In that context, observing even a small sample of M dwarfs with sensitivity to Earth-mass planets on short to moderate orbital periods will give important new insight on planetary formation. {\bf We thus focus our new \textsc{Harps} Large program on the Earth-mass regime of planet formation. We propose to intensively observe 30 M dwarfs over 3.5 years}, to reach completeness: $-$ for Earth-mass planets with orbital period up to 5 days $-$ for few Earth-mass planets with orbital periods up to the outer edge of the habitable zone ($P<50$ days). In that course, we expect to detect 20$\pm$5 new super-Earths, of which ~2-3 are Earth-mass planets and 4$\pm$2 are habitable zone super-Earths, with one planet likely to transit across its star.




This proposal is a placeholder for extra PESSTO observing runs.




We propose a HARPS radial velocity survey dedicated to the search for close-in ($\leq$ 5 AU) giant planets (GP) around young (from a few Myr to 300 Myr) stars. This survey will bring unique information on the processes at work to form GPs and the timescales associated to planet dynamical evolution, which is thought to play a major role in the early building of planetary systems and could e.g. explain the existence of Hot Jupiters. Combined with other techniques, especially direct imaging with VLT/SPHERE, and also Gaia, our survey will constrain, for the first time, the occurence of giant planets at {\it all separations} to get a unique view of GP systems architectures, test their formation and evolution processes, and to calibrate the luminosity-mass relationship of giant planets.




In recent years multi-colour and transient surveys have lead to a large increase in the number of eclipsing white dwarf plus main-sequence star binaries. These binaries offer us a chance to test some of the fundamental concepts underpinning a wide range of astrophysical problems, ranging from exoplanet studies and supernova Ia, to compact binary evolution and the age of the Galaxy. Lately we have shown that extremely precise mass and radius measurements can be made in these systems, good enough to test models of stellar structure as well as binary evolution. We now intend to extend these studies by measuring the fundamental physical parameters of a large group of eclipsing white dwarf plus main-sequence star binaries using x-shooter on the VLT. This large, uniform sample of binaries will allow us to test the evolutionary models of low-mass stars across the fully convective boundary, and test white dwarf models across their entire permitted mass range. Furthermore, it will allow us to make an accurate white dwarf luminosity function, right back to the formation of the Galaxy, and reveal whether white dwarfs in cataclysmic variables are able to grow and hence are potential supernova Ia sources.




The Planck survey is the first all-sky survey capable of blind cluster detection since the ROSAT All Sky Survey (RASS). Recently released to the general community, the Planck catalogue of Sunyaev-Zeldovich sources (PSZ) provides us with a unique sample of objects including a complete census of massive clusters ($M\ga 5\times10^{14}\,M\odot$) out to z$\sim$1 distributed across the sky. Using ESO facilities, NTT/EFOSC2 and VLT/FORS2, in a well coordinated follow-up programme including Northern telescopes, we propose to achieve the full redshift determination of the whole PSZ clusters over the 65\% cleanest sky area. Combining the redshift measurement with the SZ flux from Planck, we will estimate cluster masses for the whole catalogue, filling a unique window in the $M-z$ space with the most massive high-redshift clusters. The evolution of the mass function of this well understood catalogue will be used to put constraints on cosmological parameters, in particular $\sigma_8$ and $\Omega_{\mathrm{m}}$, with an accuracy better than 1\%. With such tight constraints, and in combination with CMB, SZ-selected clusters may put the most stringent limits on the neutrino mass. ESO-NTT and VLT are key facilities for the success of this programme, and their spectroscopic and photometric data will allow us to construct a lasting legacy catalogue of massive clusters for studies of galaxy clusters and the evolution of their constituent galaxies.




A 10-years continuous effort of sub-m/s RV measurements of quiet stars with HARPS led to a breakthrough in the field of exoplanets, unveiling a large population of Neptunes and super-Earths within $\sim$0.5\,AU for more than 50\,\% of solar-type stars in the solar vicinity. We will build upon this past experience, fully exploiting the previous observational effort, to develop a complete view of the architecture of planetary systems from compact close-in systems out to Neptunes at the ice line limit. Intensively observed stars are treasure troves in this context. The large number of observations allows for a deep census of the planetary content, a crucial aspect for the modelling of the dynamical evolution of the systems. We propose a Large Program to focus on 117 of the brightest, quiet G-K dwarfs, closest to the Sun. Our goals are 1) to characterise the full planetary content from close-in Earth mass planets to Neptunes at several AUs, 2) to improve the estimated frequency and mass distribution of terrestrial planets, a key comparison with Kepler results; 3) to derive properties of the lowest mass planets to constrain planet-formation models; 4) to provide priceless targets for space-based transit searches around bright stars with warm Spitzer and CHEOPS, and for potential further characterisation with the E-ELT; and 5) to better understand stellar phenomena. This program is only possible with HARPS.




Gaia-ESO is a public spectroscopic survey, targeting $\geq 10^5$ stars, sampling all major components of the Milky Way, from halo to star forming regions, providing the first homogeneous overview of the distributions of kinematics and elemental abundances. This alone will revolutionise knowledge of Galactic and stellar evolution. When combined with Gaia astrometry the survey will quantify the formation history and evolution of young, mature and ancient Galactic populations. The full survey is detailed on the associated Public Spectroscopic Surveys phase 1 proposal form.




We propose to obtain the first magnitude-limited, high-photometric-quality, high-temporal-resolution, multi-band survey of the rotational properties of over 60 Kuiper belt objects. The resulting data will allow us to 1) measure spin periods, and constrain shapes and bulk densities, 2) identify contact binaries or objects with extreme shapes or spins, 3) study surface colour variations, including the presence of surface spots, 4) obtain a sample of absolute magnitudes and optical colours protected from lightcurve variability, and 5) measure solar phase functions for the entire sample. Analysis of the survey data will place constraints on planetesimal accretion mechanisms and time-scales, the effects of collisional evolution with implications for dust production and mass loss in debris discs, the effects of strong early dynamical evolution in our planetary system (e.g.\ during radial displacement of mean-motion resonances due to planet migration), and allow for comparisons with main-belt asteroids and Trojans. This will be the first magnitude-limited survey of its kind to be conducted in an entirely homogeneous manner (same telescope, same observing strategy and data analysis). The data products will be a valuable resource to astronomers planning other types of observations of Kuiper belt objects, e.g.\ spectroscopic and polarimetric studies, including reassessment of archival data.




M dwarfs offer the best near-term prospects for finding and characterizing rocky, Earth-sized planets -- and for studying the characteristics and occurrence frequency of potentially habitable planets. K2, the updated Kepler mission, will find $\sim$500 small planets around M dwarfs, including 30--50 potentially habitable systems. Measuring the occurrence frequency and physical parameters of these planets will inform models of planet formation, migration, and interiors, and will provide important data for planning future missions such as CHEOPS, JWST, and PLATO. We request 65~NTT nights over 2~years to obtain medium-resolution spectroscopy of $\sim$500 K2 M dwarfs hosting transiting planets in order to {\bf characterize the host stars, refine stellar and planetary parameters, measure the occurrence rate of habitable rocky planets around low-mass stars, optimize target selection for CHEOPS and PLATO, and find a few good targets for early-science JWST atmospheric characterization.}




The carriers of $>$400 broad interstellar absorption features, imprinted on stellar spectra, pose the oldest mystery in astronomical spectroscopy. Any identification of an individual or set of carriers of these diffuse interstellar bands (DIBs) will provide a unique tool to probe the organic content and physical conditions of the ISM in galaxies. We propose to undertake a large and systematic study of the physical and chemical parameters that influence the DIBs, allowing us to ``reverse engineer'' key molecular carrier properties. With EDIBLES we will determine (1) the chemical composition of DIB carriers by studying their relation to interstellar elemental abundances (depletion), (2) the relation between weak and strong diffuse bands through identifying DIB sequences, and (3) the physical-chemical parameters that influence the DIB properties from observed molecular transitions linked with PDR models. This requires a high-precision (S/N$\sim$1000, R$\sim$100\,000) UV/VIS survey of 159 interstellar sightlines with well determined interstellar dust properties. This is achieved most efficiently with UVES-VLT in service/filler mode. EDIBLES will provide the input for comparison with dedicated laboratory programs, and has significant legacy value in terms of complementary stellar astrophysics studies. EDIBLES was ranked favourably in period 93, but was not scheduled due to technical reasons that are now resolved.




The detection of extra-solar planets with masses in the Super-Earth and Neptune mass regime represents a benchmark for planet surveys. With the number of detections growing the properties and true frequency of such systems are slowly being accessed. However, due to historical selection biases, the frequency of Neptune and Super-Earth planets has not been systematically probed in the metal-poor regime. Planet formation models strongly suggest that Neptunes and Super-Earths should be frequent around stars of low metallicity, contrarily to the case for giant planets. This prediction needs, however, to be throughly tested. We propose to continue the survey started in P90 to test this theoretical finding, by using the HARPS spectrograph to search for very low mass exoplanets around a sample of solar-type stars with metallicities ([Fe/H])$<-$0.4\,dex. Results from our initial Large Program (P90-95) revealed several promising candidates, though more observations are needed for a solid detection. Interestingly, however, the results also suggest that the frequency of low mass planets in the sample may be significantly lower than the expected from models. If confirmed, this result will have strong implications for the theories of planet formation and evolution, as well as to our understanding of the frequency of Earth-like planets in the Galaxy.




Planets and brown dwarfs in close orbits will interact with their host stars, as soon as they evolve to become red giants. However, the outcome of those interactions is still unclear. Recently, several brown dwarfs have been discovered orbiting hot subdwarf stars (sdB) in very short orbital periods of $0.065-0.096\,{\rm d}$. Those compact helium stars are the stripped cores of giants, which lost their envelopes due to the interaction with a close companion. More than $3\%$ of those stars might have close substellar companions. This shows that such companions can significantly affect late stellar evolution and that sdB binaries are ideal objects to study this influence. Thirty-six new eclipsing sdB binary systems with cool low-mass companions were discovered based on their lightcurves by the OGLE project. We want to use this unique and homogeneously selected sample to derive the mass distribution of the companions, constrain the fraction of substellar companions and determine the minimum mass needed to strip off the red-giant envelope. We are especially interested in testing models that predict hot Jupiter planets as possible companions. Here we propose a large filler programme stretched over 4 semesters to obtain 113 hours time-resolved spectroscopy with FORS2 to measure the RV-curves of the 23 HW Vir systems with the shortest periods to determine the companion masses.




Theoretical models of AGN radiative feedback predict that AGN-driven, galaxy wide massive outflows are not a rare and peculiar phenomenon, but a fundamental process affecting the bulk of the baryons in the universe. Currently, sparse observational evidence of AGN feedback exists at z$>1$ but mostly limited to high luminosity objects, therefore a comprehensive picture is still far from being reached. The time is ripe for a systematic approach. We propose a SINFONI Large Programme, SUPER, aimed at carrying out the first statistically-sound investigation of ionized outflows in AGN host galaxies at the peak epoch of AGN and galaxy assembly, z$\approx 2$. SUPER is designed to map the ionized gas kinematics ([OIII], \hbeta, \halpha) with $\sim 1$ kpc spatial resolution, by exploiting the SINFONI AO capabilities, in a sample probing four orders of magnitude in AGN bolometric luminosity. SUPER will deliver tight scaling relations between the frequency, mass, mass flow rate and momentum rate of ionized outflows, and AGN bolometric luminosity and Eddington ratio, which can be directly plugged into models of galaxy evolution. SUPER will constrain the morphology of different kinematical components, fast outflowing gas versus quiescent star-forming gas, directly probing the effect of outflows on the star-formation processes and galaxy shaping.




Gas inflows and outflows regulate the evolution of galaxies, and in particular their star formation histories. Observations of galaxies from which gas is being removed are obtained at various wavelengths, and individual extreme examples of gas stripping are known, including the so-called jellyfish galaxies. Thanks to its field-of-view and high sensitivity, MUSE@VLT allows for the first time a systematic and detailed investigation of gas removal processes in a statistically significant sample of galaxies. We propose a MUSE large program to observe 100 galaxies with optical signatures of stripped material located in different environmental conditions. They are homogeneously selected in clusters and in the field, and belong to dark matter haloes with masses covering over three orders of magnitude. The focus of this program is on the regions {\sl outside of galaxies}, where there is evidence for stripped material, in the vicinity and out to large distances from the parent galaxy. The MUSE data will clarify how, where and why stripping occurs, measure its timescale and efficiency as a function of galaxy mass and environment, and quantify the amount of star formation involved in this process. This program will provide a unique dataset for understanding the mechanisms responsible for gas stripping and the cause of star formation quenching in galaxies.




How did galaxies reionize the universe? How do gas and metals cycle in and out of galaxies? Despite recent progress, these fundamental questions are still open, because even the deepest blank field surveys have insufficient depth and resolution. Our innovative HST Program (GLASS) addresses these two questions by taking slitless spectra of galaxies magnified by foreground clusters. Assisted by lensing magnification, we can study sources that are an order of magnitude fainter and smaller than possible in blank fields. However, the spectral resolution of GLASS is insufficient to measure line shapes. We propose to use the unique capabilities of KMOS to secure the redshift identification of $\sim$25 emission line galaxies, consistent with being \lya\ at $z > 7$, including 6 at $z > 8$ - which would be the highest $z$ \lya\ ever confirmed. By targeting known line emitters, our survey is several times more efficient than searches based on photometric selection. This will be by far the largest sample ever collected at $z>7$, sufficient to finally constrain the \lya\ optical depth and the timescale of reionization. At the same time, KMOS will provide kinematics of $\sim$150 galaxies at $z=1-3$, for which GLASS-HST spectra provide metallicity measures. This will extend for the first time correlations between kinematic properties, mass and metallicity over a range in stellar mass sufficient to provide a key test of feedback models.