Abstracts of Large Programmes and Public Spectroscopic Surveys scheduled in Period 101

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



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.




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.




We propose a large, high-resolution (R$\sim$20,000) VISIR survey of atomic and molecular gas in the planet-forming regions of protoplanetary disks. The survey will produce a transformative data set designed to address many pending questions about the origin of exoplanets, their composition and ultimately their habitability: (i) The timescale and mechanism for gas dissipation; (ii) the significance, chemistry and dynamics of photo-evaporative disks winds; (iii) the disk vertical thermo-chemical structure and its relation to the hardness and strength of its radiation environment; (iv) the nature of protoplanetary chemistry and inner disks surfaces as chemical factories. About 50 disks have been selected from extensive spectroscopic Spitzer and Herschel surveys covering the optically thick, strongly accreting, primordial stage at $\sim$1 Myr to the transitional disk phase at $\gtrsim$5-10 Myr. The sample spans a stellar mass range from Solar-type (0.5-1.0 $M_{\odot}$) to Herbig Ae stars (2.0-3.0 $M_{\odot}$). We target the [NeII] 12.81\,$\mu$m line and strong rotational lines of water and OH around 12.27 and 12.4\,$\mu$m, tracing progressively deeper layers of the disk surface at radii of 1-10 AU. A large coordinated effort is necessary to assure that both atomic and molecular tracers of disks are observed uniformly for the same sample. Carrying out a large VISIR programme now is critical for the community to make the best use of JWST.




The small worlds detected by the Kepler telescope revealed new kinds of planets ranging from very low-mass, low-density planets to massive super-Earths. These objects are challenging all planet formation theories and no example of them exist in the solar system (so far). To better understand the formation of these small worlds (including the Earth), we need to precisely characterise a large population of such planets. As of today, only a dozen low-mass planets have been well characterised (mass constrained to better than 20\%), which allows one to unambiguously determine whether they are rocky or gaseous, and to infer their composition. With this large programme proposal, we want to precisely characterise up to 18 new low-mass planets already detected to transit relatively bright and quiet G -- K dwarfs, as seen in the K2 (the second life of the Kepler space telescope) photometric data. They have planetary radius in the range 1.5 -- 6 R$_{\oplus}$, hence spanning different planet populations. For that, we are requesting a total of 70 HARPS nights spread over 4 semesters. These low-mass planets will provide substantially new constraints to test small planet formation theories. As the stars are relatively bright, this proposal will also provide key targets for atmospheric characterisation of low-mass planets with upcoming instruments like the JWST and the E-ELT.




Transits across small stars represent the best opportunities to measure the bulk and atmospheric compositions of exo-Earths and super-Earths. Much interest is thus focused on terrestrial mass planets transiting M~dwarfs, ideally in the habitable zone of their host stars. Our new Harps Large Program thus focuses on the identification, validation, and characterization of planets transiting M~dwarfs. In particular, we propose : - to derive more precise masses of confirmed planets K2-3bcd, GJ1214b, GJ1132b, and GJ3470b, - to confirm, and then measure preliminary masses for, new transit candidates identified by K2 and MEarth, - to prepare transit searches for known short-period RV planets which have not been searched for transits so far, - in that course, to search for additional planets in all these systems. \smallskip Better masses are critical to understanding the formation and composition for many of the known super-Earths, which typically have much more precise radii than masses. New, smaller, cooler planets amenable to atmospheric characterisation will be most precious for upcoming JWST and ELT programs. Assuredly, such a program will have a high impact in the field of exoplanetary science.




Asteroids in our solar system are metallic, rocky and/or icy objects, ranging in size from a few meters to a few hundreds of kilometers. Whereas we now possess constraints for the surface composition of most D$\geq$100 km primordial main-belt asteroids, little is known regarding their internal structure. Yet, this is a fundamental property whose characteristics result directly from (a) their formation location, (b) their time of formation, and (c) their collisional history. Characterizing the internal structure of the main compositional classes of asteroids would therefore allow us to address entirely new questions regarding the earliest stages of planetesimal formation and their subsequent collisional and dynamical evolution. To achieve this goal, we propose - for a modest amount of observing time ($\sim$3 nights/semester) - to carry out disk-resolved observations of a substantial fraction of all D$\geq$100 km main-belt asteroids (sampling the four main compositional classes) at high angular-resolution with VLT/SPHERE throughout their rotation. These observations will enable us to derive their volume (via their 3-D shape) which combined with already existing mass estimates will allow us to determine their bulk density and hence to characterize their internal structure. Such information will, in turn, provide unprecedented constraints on solar system formation models such as the Nice and Grand Tack models.




Novel wide-field synoptic surveys of the sky, combined with multi-wavelength and multi-messenger experiments, mean we have now entered a golden age in transient astronomy. PESSTO has changed the way such transient science is carried out within ESO, and has prepared us for these new surveys by gathering the ESO supernova community into one coherent team, making the NTT a key global facility (50+ papers). We have provided legacy datasets for the most luminous supernovae, unusual tidal disruption flares, faint transients in remote halo locations, and quantified how interaction powers the fastest and most unusual supernovae. The SOXS spectrometer has now been selected by ESO to replace EFOSC2 and SOFI in 2020, dedicating the NTT to time-domain astronomy in the next decade. We now propose `extended'-PESSTO (ePESSTO), building on the success of our PESSTO consortium and bridging the gap to SOXS. We will broaden the science to include of GRBs, gravitational wave sources, and high energy neutrinos, and will focus on the most exciting new transient populations now being discovered. The new all-sky surveys of Gaia, ASASSN, ATLAS and the upcoming Pan-STARRS2 and Zwicky Transient Facility demand extensive spectroscopic follow-up which we, the ESO community, are well placed to lead. We will continue to make all reduced data public as we do for PESSTO.




Thousands of transiting exoplanets are known today but not many have been studied in transmission. While a diversity of atmosphere types is starting to emerge, it is not yet possible to draw robust conclusions about the underlying population owing to the small sample size. We propose to perform the first large-scale ground-based transmission spectral survey of twenty exoplanets with FORS2 across the full range of physical properties. This will be greatly aided by the unprecedented access {\it{VLT}}~with~FORS2 provides to the abundance of fainter systems that {\it{HST}} cannot observe. Obtaining {\it{HST}}-quality transmission spectroscopy with FORS2, our group and others have already demonstrated FORS2's capability, with detections of Na and K absorption and scattering by clouds/hazes in the atmospheres of several exoplanets. We have also used FORS2 to rule out a hydrogen dominated atmosphere of an Earth-mass exoplanet, proving the instrument's high potential to characterize exoplanets. Our proposed FORS2 survey, combined with our ongoing {\it{HST}} survey, will increase the number of characterized transiting exoplanet atmospheres by a factor of $5\times$. This will represent a dramatic step forward in the field, allowing us to perform the first serious investigation into the relationship between clouds/hazes and fundamental properties such as mass, radius, temperature, and metallicity.




The nature of dark energy is one of the most enigmatic questions in Physics research. Cosmological surveys are now driving ambitious observational programmes to study the nature of dark energy. ESO is conducting the KiDS survey for this purpose and Europe is currently leading this effort from space with the upcoming Euclid mission, which has gathered wide support from the European research community. Weak lensing mapping of the dark matter distribution has emerged as the potentially most powerful observable to map the structure of the universe. In order to reach the full scientific potential of the weak lensing probe, we need to use photometric redshifts to determine the distances of the sheared galaxies. For that purpose, we need to know the mapping between colour space and redshift. However, if we explore the distribution of observed galaxy colours, we realize that there are regions of colour space ($\sim$50\%) which have not been explored. The properties, including redshifts, of galaxies in these regions are unknown. We want to fill this gap taking spectra of these galaxies ($\sim$2500 in this proposal) to properly map the redshift distribution of all galaxies and boost the dark energy Figure of Merit by a factor $\sim$4 to enable Euclid reach its scientific goals which otherwise are compromised. Mapping these galaxies will also help fill a gap in our coverage and knowledge of the galaxy population.




SPHERE, the VLT's new generation planet imager, provides exquisite exoplanet detection performance owing to a combination of high-order XAO correction, coronography, and differential imaging technics in visible and near-infrared. These capabilities enable the detection of faint planets at small angular separations from bright stars. The SHINE program for SPHERE High-contrast ImagiNg survey for Exoplanets, a significant component of the consortium Guaranteed Time Observations, is a large near-infrared survey of 400-600 young, nearby stars. The scientific goals are: i) to characterize known planetary systems (architecture, orbit, stability, luminosity, atmosphere); ii) to search for new planetary systems using SPHERE's unprecedented performance; and finally iii) to determine the occurrence and orbital and mass function properties of the wide-orbit, giant planet population as a function of the stellar host mass and age. Combined, the results will increase our understanding of planetary atmospheric physics and the processes of planetary formation and evolution. To explore the origin of planetary formation a small fraction of the GTO Large Programme is also devoted to the study of proto-planetary and debris disks, using a variety of SPHERE instrument modes optimized for these tasks.




We propose to take the next leap forward in our view of the universe through a \hour\ MUSE Ultra Deep Field (MUDF), which will stimulate progress in multiple fields of astrophysics by reaching the faintest flux limits ever obtained for emission lines. To maximise the science impact of the MUDF, we have selected the unique field \qso\ with two bright $z\sim 3.22$ quasars, separated by 500 kpc, which act as ``light bulbs'' to trace in absorption the distribution of the diffuse cosmic gas. The powerful synergy of absorption and emission diagnostics in the MUDF will allow us to: (i) redefine our view of the matter distribution at $z\sim3$, enabling the first detection of the cosmic web in emission; (ii) provide a definite picture of how the flow of gas inside halos shape the evolution of galaxies; (iii) open a new window to study the link between quasars and their environment by glimpsing at the assembly of a massive cluster during its infancy; (iv) obtain a new vantage point on how the Hubble sequence emerges from over 10 billion years of cosmic evolution in a rich dataset of over 400 galaxies between $z\sim 0-6.5$. The transformational MUDF will be a long-lasting legacy for the VLT, it will open a new discovery space, and it will be a prime spectroscopic survey that the ESO community will exploit in the coming decade in synergy with campaigns at world-class observatories like {\it JWST} and ALMA.




We request MUSE mosaics to map the star forming disks of 20 nearby galaxies. These data will be combined with in-hand PHANGS-ALMA high angular resolution CO data (17 galaxies from our programs plus 3 archival datasets). The aim of the proposal is to obtain for the first time a comprehensive view of the chemo-dynamical evolution of the star formation process across the different ISM environments present within a representative sample of nearby massive star forming main sequence galaxies . In particular we will (a) estimate the timescales of the star forming process (i.e. molecular cloud lifetimes, feedback lifetimes, feedback outflow velocities, star formation efficiencies, mass loading factors), (b) quantify the importance of star formation feedback in galactic disks, and (c) study chemical enrichment and mixing in radial and azimuthal direction (via $\sim$40,000 fully characterized HII regions). All these aspects will be linked to the local conditions under which star formation proceeds in disks (e.g. gravitational potential, ISM pressure, local dynamics, local radiation field and shielding), which at the same time are connected to global properties of galaxies such as the stellar mass, star formation rate, morphology, nuclear activity, and environment. Building this connection will inform the next generation of theoretical models and simulations, finally bridging the fields of star formation and galaxy evolution.




We propose to continue and complete our deep NaCo $L^{\prime}$-band coronagraphic angular differential imaging GTO survey for wide-separation giant planets around nearby young stars with circumstellar disks. Our main goal is the revelation and characterisation of the observationally not yet well-characterised wide-separation \mbox{($>$5-10\,au)} giant planet population during the time of formation and dynamical evolution. Our survey is therefore focused on stars with protoplanetary transition disks and with well-characterised debris disks, many of which show signatures of dynamical activity that could indicate the presence of giant planets. With the combination of $L^{\prime}$-band observations, the use of the AGPM coronagraph to minimise the inner working angle for bright stars, and a strategy for going significantly deeper than previous surveys, we optimise the sensitivity to both more embedded (younger) as well as cooler (lower-mass and older) planets than targeted by previous/other surveys. We also probe smaller separations, thus bridging the gap between orbital separations probed by RV and previous direct imaging surveys. Our GTO survey is distinguished from and complementary to other state-of-the-art exoplanet imaging surveys like SPHERE-SHINE by the focus on stars with planet formation-related circumstellar disks and by covering a different parameter range by exploiting the unique $L^{\prime}$-band capability of NaCo.




The discovery of gravitational wave radiation from merging black holes (BHs) also brought the discovery of stellar-mass black holes of masses above 30 M$_\odot$. Prior to the gravitational wave discoveries the most massive stellar-mass BH known had a mass of $<15$M$_\odot$. Whereas peculiar binary evolution effects or even the existence of primordial BHs could be invoked to explain the different BH masses, the current sample of 17 Galactic low-mass X-ray binaries with dynamically determined BH masses is severely biased to sources at high Galactic latitude ($b$). Given the observed and theoretical evidence of BH kick distributions, this means that the current sample is biased against the most massive BHs in X-ray binaries. We propose to remove this selection bias as all-but-one of our target BH X-ray binaries have $|b<1^\circ|$. This is a concerted effort from the VLT, Keck and GTC (each targeting 6/2/3 BHs, respectively). After we remove the main bias(es) that plague the current sample, the mass distribution of stellar-mass BHs will inform supernova and binary evolution models, including those seeking to explaining the origin of the gravitational wave events.




We propose to perform an ultra-deep observation of 160 hours of a single 1 arcmin$^2$ MUSE field in the UDF area. The additional depth, together with the improved spatial resolution brought by the GALACSI adaptive optics module, has the potential to revolutionize our understanding of galaxy formation and evolution, comparable in impact to the Hubble (Ultra) Deep Fields of the last two decades. Observing part of the UDF to an unprecedented depth with MUSE (4.3 \ergs{-20} 3$\sigma$ point-source sensitivity) has a huge potential for discoveries. It will enable for example the detection of several hundreds of galaxies purely from their \lya\ emission lines, with a continuum magnitude $m_{AB}\sim$32 beyond the limits of JWST imaging. It will also provide a wealth of information on galaxies and their environment: e.g. the search of the IGM in emission, the faint end of the \lya\ luminosity function at z$\sim$6, the physics of the ISM of z$<$4 galaxies, the characterization of the \lya\ haloes, the kinematics and spatially resolved properties of z$<$3 galaxies.




The most promising way to understand the complex process of planet formation is to study its outcomes in a range of formation environments, and evaluate how those environments influence the outcomes. Stellar mass and metallicity are two parameters that are known to have a significant impact on the prevalence of giant planets. The effects of metallicity are reasonably well studied, at least for Sun-like stars, while stellar mass dependencies have been more elusive, primarily due to technical difficulties. Here, we propose a large high-contrast imaging survey for 83 B-type stars in the Sco-Cen region. Sco-Cen is already being surveyed at $\sim$1--3~$M_{\rm sun}$ ($\sim$A/F/G-type) with direct imaging, and has been very fruitful due to a favourable proximity ($\sim$120--150~pc) and age ($\sim$10--16)~Myr. Scalings from lower-mass populations and previous imaging detections imply that B-type stars may be the richest hosts of detectable giant planets, but a large dedicated survey is required to uncover and characterize this hypothesized planet population. By comparing our B-star results to the existing surveys of $\sim$1--3~$M_{\rm sun}$ Sco-Cen members, we can eliminate dependencies of formation environments (including metallicity), and thus cleanly isolate stellar mass as the dominant parameter in our statistical study.




\veils, the VISTA Extragalactic Infrared Legacy Survey, is a new ESO Public Survey, covering 9 sqrdeg of extragalactic legacy fields with deep, cadenced observations. The innovative aspect of \veils\ is its design enabling the first wide-field $J$ and $Ks$-band extragalactic time domain survey. The goal of this time-domain survey is to use two independent standardisable candles -- type Ia supernovae and AGN dust time-lags -- to significantly improve constraints of cosmological parameters in a complementary way to BAO, weak lensing, or the CMB. In addition, we will search for new members of a recently discovered class of optically-elusive, infrared-bright transients. With the proposed Large Programme VOILETTE (= VEILS OptIcal Lightcurves of Extragalactic TransienT Events), we are seeking the crucial optical time-domain support to enable the transient science of \veils\ as the Dark Energy Survey is finishing. VOILETTE will use the VST to obtain cadenced $griz$ observations of the \veils\ fields to (1) discover, classify, and build light curves of new type Ia supernovae, (2) monitor the optical variability of AGN to determine dust time lags, and (3) support identification of infrared transients with and without an optical counterpart.




The closest massive star forming region, Sco-Cen, has been recognized in recent years as a unique niche for extrasolar planetary systems studies. Indeed, several extrasolar planets have been found by direct imaging in this association, as well as many debris disks, possible signposts of past giant and on-going terrestrial planet formation. A few systems orbit binary stars have been found, giving thus the opportunity to study planet formation and early dynamical evolution in a unique way. We propose a HARPS survey to search for planets with semi major axis less than typically 2 au around a sample of 112 young stars members of Sco-Cen, already observed or to be observed under SPHERE GTO. Coupling HARPS, SPHERE and GAIA data will allow a full exploration of each star environment, from a fraction of au to hundreds of AU. This will be the first exhaustive GP survey around stars with similar, well known ages, providing thus a detailed comparison with formation models. Other outputs of our program include a search for comet evaporation around our target stars, and the characterization of the stars themselves.




Planets orbiting both stars of a binary system -circumbinary planets- are challenging our understanding about how planets are assembled and how their orbits subsequently evolve. We aim to assess how similar and how different the orbital and physical properties of circumbinary planets are to the properties of planets orbiting single stars. Our detections will open a new window of investigation into a highly debated topic, and complement observations of circumbinary protoplanetary discs imaged with SPHERE and ALMA. \smallskip During 78 nights, our programme will turn HARPS on a unique and carefully selected sample of 40, bright, recently identified, single-line, low-mass, eclipsing binary systems. They have been discovered and characterised in the course of a 10-year long observing campaign. Composed of an F, G, or K + late-M pair, their mass ratios provide optimal conditions for high radial-velocity precision and accuracy, reaching a level where the detection of circumbinary planets with the mass of Neptune is feasible. Based on already discovered systems, we expect to find between 5 and 15 planetary systems orbiting our eclipsing binaries. Discovering them using the radial-velocity method also opens the door to study dynamical effects unique to circumbinary planets, to estimate their multiplicity, and to compute their true occurrence rate, information that has eluded {\it Kepler}.