Abstracts of Large Programmes and Public Spectroscopic Surveys scheduled in Period 100

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



Our view of gas flows inside the halos of $z > 3$ galaxies is hampered by the faint UV stellar continuum, which prevents mapping inflows and outflows in absorption using spectra of individual galaxies. Therefore, to study how gas flows regulate galaxy evolution at $z > 3$, one must discover and analyse strong absorption line systems (SALs) towards bright background quasars with foreground galaxies near to the line of sight. However, due to the intrinsic inefficiency of multi-object spectrographs, only a handful of such galaxy-absorber pairs are currently known at these redshifts; this leaves theoretical models for cold flows and feedback nearly unconstrained. We propose to exploit MUSE to conduct a deep redshift survey of $z>3$ Ly$\alpha$ emitting galaxies, complete to luminosities of $0.1L_*$ within $250$ kpc of 22 quasars, for which exquisite archival high-resolution spectroscopy reveals the presence of 37 SALs. Our observations will identify tens of galaxy/strong-absorber pairs, with which we will: i) map the radial profile of hydrogen and metals near to $z>3$ galaxies, uniquely constraining models of inflows and outflows; ii) resolve the denser halo gas associated to SALs in emission; iii) characterise the environment of the SAL population probed by quasar surveys. The proposed observations will be a legacy for studies of the galaxy-IGM connection, the $z>3.5$ quasar environment, and the halo gas of $z\sim 1$ [OII] emitters.




In spite of the recent advances, the complex astrophysics in high-redshift star-forming regions and how it evolves with time remains poorly constrained. A clear lack of spatial resolution and the difficulty to access all the necessary line diagnostics, have so far led to conflicting results. We thus propose a large programme with KMOS to observe and spatially resolve 200 galaxies at 1$<$z$<$2.5 with full near-IR wavelength coverage (YJ,H,K) delivering the (nearly) full set of rest-frame optical nebular lines and therefore an extraordinary diagnostic power. The programme will use both lensed galaxies in very well studied HST-CLASH clusters fields to exploit the magnification boosting sensitivity and angular resolution, complemented by a sample of more massive unlensed galaxies to fully explore the Mass-SFR plane. The main aim is to understand how the physical conditions across the galaxy evolve with cosmic time as well as the interplay between key processes such as excitation mechanisms, metal enrichment, ionisation parameter, metallicity gradients, SFR, gas inflows and outflows. The observing programme is designed to exploit the spatially resolved full set of diagnostics to provide the first statistically sound determination of the astrophysics of high-z galaxies, producing some of the most sensitive and powerful constraints to investigate galaxy evolution.




The Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect is a torque due to both incident solar radiation pressure and the recoil effect from the anisotropic emission of thermal photons on small bodies in the Solar System. It can modify their rotation rates and spin-axis orientations or obliquities and can explain many observed phenomena in asteroidal science. YORP is also a proposed mechanism for binary formation through equatorial mass loss and re-aggregation. In Period 85 we were awarded Large Programme status on the NTT+EFOSC2 for detection of the YORP effect on a large sample of Near-Earth Asteroids from phase shifts of rotational light curves over at least 4 years of observation (185.C-1033). The programme was supported by a Large Programme on VLT+VISIR (185.C-1034 and 190.C-0357) to obtain thermal infrared photometry. The latter VISIR programme (190.C-0357) was never completed due to technical issues with VISIR. This proposal is to recover the lost time to continue the thermal-IR component of the programme. Thermal infrared photometry from VISIR is required to constrain the sizes, albedos and thermal inertias, which are crucial input for thermophysical models to predict the strength of the YORP effect. These predictions can then be compared with observed measurements, to allow models of radiative torques to be refined.




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 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.




The Dark Energy Survey (DES) supernova program has completed the first 3 of its 5 years of observations, resulting in over 1500 likely type Ia supernova (SN\,Ia) candidates, with over 200 spectroscopically confirmed SNe\,Ia. Over 60\% of the classifications at $z>0.5$ have been obtained from our VLT program. We propose to complete our program for the last 2 years of DES to determine types and redshifts at VLT for a further 80 DES SNe residing in faint host galaxies, for which accurate redshifts and SN types cannot otherwise be determined. Most DES SNe will be photometrically classified using the DES $griz$ light curves combined with host-galaxy spectroscopic redshifts from our 100-night AAT/OzDES program, measured once the supernovae fade. However, $\sim20\%$ of the DES SNe\,Ia will lie in galaxies too faint ($r$$>$23.5) for this technique. These are the highest-redshift SNe\,Ia in DES and this program will ensure they are included in our cosmological analyses, vital for an accurate determination of the equation-of-state of dark energy, $w(a)$. Critically, as the SN\,Ia luminosity correlates with host-galaxy intrinsic brightness, our proposal will remove redshift-dependent biases in the DES measurement of dark energy. Further, for the first time, our proposal provides a census of SNe in low-metallicity environments, including super-Chandrasekhar SNe\,Ia, superluminous supernovae, and peculiar core-collapse supernova events.




We propose to continue our deep NaCo $L^{\prime}$-band coronagraphic angular differential imaging GTO survey for wide-separation giant planets around nearby young stars. Our main goal is the revelation and characterisation of the hypothesised, but observationally only partially characterised wide-separation \mbox{($>$5-10\,au)} giant planet population during the time of formation (protoplanetary disks) and dynamical evolution (debris disks). At this stage of the survey, we only target stars with protoplanetary transition disks and well-characterised debris disks with signatures of dynamical activity that could hint towards 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 will optimise the sensitivity to both more embedded (younger) as well as cooler (lower-mass and older) planets than targeted by other surveys. We will also probe smaller separations, thus bridging the gap between orbital separations probed by radial velocity and direct imaging surveys. Our GTO survey is distinguished from 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.




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 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 a uniquely {\it deep} VLT spectroscopic survey of high-redshift galaxies, carefully designed to exploit the multi-wavelength imaging and near-IR grism spectroscopy available in two CANDELS fields, namely UDS and CDFS. The aim of this proposal is to move beyond redshift acquisition, obtaining spectra with high enough signal-to-noise to perform a global spectral analysis, deriving metallicities and velocity offsets from absorption and emission lines in star forming galaxies, and detecting the $Mg_ {UV}$ features in massive passive galaxies. Such deep observations in statistically significant samples, will allow for the first time a detailed investigation of the physics of galaxy evolution in the early Universe. Using integration times of $20



van der Wel

We propose a deep spectroscopic survey to determine the physical properties of galaxies when the Universe was half its present age. This is not a redshift survey; rather, the proposed observations of $z=0.6-1.0$ galaxies in the COSMOS/UltraVISTA field will provide a homogeneous set of deep spectra ($S/N>10~\rm{\AA}^{-1}$) at high resolution ($R=2500$) to determine the stellar population properties and dynamics of nearly 3000 galaxies with stellar masses down to $2\times 10^{10}~M_{\odot}$. In their quality, these spectra will constitute the equivalent of the SDSS spectra that revolutionized our understanding of present-day galaxies. The unique combination of spectroscopic and kinematic tracers, complemented by existing HST imaging and a large, multi-wavelength photometric dataset, will provide a public legacy for many galaxy evolution studies. The dataset will remain unsurpassed for many years and provides an indispensable benchmark for JWST programs at higher redshifts.



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Last update: OPO - July 31, 2017