Abstracts of Large Programmes and Public Spectroscopic Surveys scheduled in Period 110

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



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.




We propose an ambitious program to characterize, in terms of mass, radius, and density, at least 20 small transiting planets (1--4\,R$_\oplus$). By determining planetary masses to better than 10-15\%, we will be able to distinguish between internal structure models, and determine whether these systems are silicate-based planets like our Moon, planets with an iron core like the Earth, or even denser systems like Mercury. We will do so by conducting HARPS radial velocity (RV) observations of planets detected to transit by the Transiting Exoplanet Survey Satellite (\textit{TESS}), scheduled for launch in April 2018. Our extensive experience with planet detection and characterization for the \textit{K2} mission, will allow our \textit{KESPRINT} team to carry out quick and efficient \textit{TESS} transiting planet detection and vetting, and carry out a systematic RV characterization campaign. The detailed characterization of small transiting planets, enabled by the bright stars to be observed by \textit{TESS}, is key to understand planet formation. Our observations will provide constraints on photo-evaporation models and models of planet formation, by investigating the core composition of super-Earth planets and ultra-short period planets (USPs) that have lost their atmospheres. We will further investigate the population of sub-Neptune planets and identify key targets for future atmospheric studies such as with the James Webb Space Telescope.




We propose to obtain several new MUSE Deep Fields of $t_{\mathrm{exp}} = 25^{\mathrm{h}}$ in blank-sky locations with ultra-deep HST multiband imaging and other ancillary data available. Our selected targets are the four parallel fields of the Hubble Frontier Fields legacy programme that are accessible to the VLT. Our observing strategy is guided by a combination of several science drivers: (1) Obtain spatially resolved spectroscopy of typical Lyman-$\alpha$ haloes at redshifts $z>3$, to constrain the physical nature of the halo gas and the dominant powering mechanism for the Ly$\alpha$ radiation. (2) Identify significant overdensities in the distribution of Ly$\alpha$ emitters and test previous claims that Lyman-$\alpha$ halo properties depend on the environment. (3) Build a statistically significant sample of galaxies out to $z\simeq 1$ for spatially resolved kinematic and dynamical analyses. These new observations will triple the number of MUSE Deep Fields, provide statistically independent locations to combat cosmic sample variance, and substantially improve in image quality over our previous deep fields efforts through the use of Ground-Layer Adaptive Optics. The new Deep Fields will be embedded in small mosaics of $2^{\mathrm{h}}$--$5^{\mathrm{h}}$ depth to mitigate edge effects, characterise the environments, and to increase the general legacy value of this survey by covering the full footprints of the HST images.




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. Only twelve binary systems are currently known to host circumbinary planets. However, HARPS radial-velocities collected in the past two years have revealed the presence of circumbinary planet candidates in 15 new systems. With this proposal, we request time on HARPS to confirm 15 planetary candidates which can double the total number of known circumbinary systems. We will also search for longer period and lower mass planets on 20 stable systems, and will monitor a sub-sample of 10 bright new binaries identified by TESS and KELT for new candidates.




Fast radio bursts (FRBs) have in the last few years emerged as a rich field for the study of compact objects, magnetized plasma, galaxy formation, and cosmology. Now, technical advances are shifting the emphasis from discovery science to robust statistical analysis. With this Large Programme, we will leverage the imaging and spectroscopic capabilities of the VLT to perform the first large and homogeneous survey of FRB host galaxies. With a sample of 50 FRBs defined by strict selection criteria, we will address two primary science goals: 1) test the leading FRB progenitor models and emission mechanisms through detailed measurements of their host galaxy environments, examining their connection to the underlying stellar population and interstellar medium; and 2) combine FRB dispersion measures and redshifts to assess the distribution of baryons in the low-redshift intergalactic medium and thereby constrain the processes of feedback during galaxy formation. For this, we rely on deep images to identify the hosts, complete redshift determinations, and spectroscopic and photometric data to characterize the stellar populations and physical properties of the hosts. This dataset will set the benchmark for all future FRB surveys and will lay the foundation for numerous follow-up activities. As such, we will rapidly disseminate the data and results to the community through publications and dedicated repositories.




We propose to explore with HARPS the inner region of planetary systems orbiting nearby G & K dwarfs known to host giant planets beyond the ice-line. Probing the global architecture of planetary systems is extremely challenging, and there is a very limited number of systems for which the planetary content of both the inner and outer parts have been explored. This leads to poor observational constraints on planet formation theories. Actually, the two main branches of formation theories, in-situ formation and inward-migration, predict radically different occurrences of close-in super-Earths and Neptune-type planets in presence of a cold giant. The former anticipates a correlation between the populations of close-in low-mass planets and cold giants, while the latter predicts an anti-correlation. In this LP, we aim to determine the occurrence of close-in super-Earths and Neptunes in systems hosting a cold giant. Recently, several attempts to estimate this occurrence have lead to contradictory results due to small number statistics and biases. Here, we take advantage of the 22-year-long CORALIE radial velocity survey, composed of 1647 main sequence G & K dwarfs limited in volume at 50 pc, to select a sub-sample of 50 stars known to host a giant planet beyond 1 AU. Among these 50 systems, only 5 targets have been intensively monitored by HARPS so far, and 15 are currently being monitored as part of a running GTO programme (not related to this proposal). We propose to monitor the 30 remaining systems, with a total of 75 HARPS measurements per target, to search for low-mass close-in planets. We show that our sample size combined to the proposed observing strategy will allow for a robust determination of the occurrence of close-in super-Earths and Neptunes with cold giants and settle the question of the correlation between these populations. It will thus provide a fundamental observational constraints on planet formation theories.




We propose to conduct a major survey of about 1.4 Sq. Deg. in the COSMOS field with CONCERTO to map in 3D the fluctuations of the [CII] line intensity, in the reionisation and post-reionisation epoch. Our survey will exploit a technique known as "intensity mapping" which probes cosmic structures by measuring the aggregate line emission from all galaxies across redshift. The [CII] line is a promising choice for its brightness and its role as a tracer of diffuse gas and star-formation activity in the interstellar medium. Our survey will give the first constraints on the power spectrum of [CII]-emitting galaxies at z ? 5, allowing us to measure the typical halo mass scale of star-forming galaxies, the star formation rate density, and the number counts of [CII]-emitters as a function of redshift. The average interstellar medium conditions in high-z galaxies will be investigated using cross-power spectra of the [CII] line with the other lines present in the CONCERTO bandpass ([OI] 145 ?m, [NII] 122 ?m and [NII] 205 ?m). Cross-correlation and synergies with galaxy surveys will be used for foreground removal and will provide additional astrophysical information, as on early metal enrichment and global history of reionization. Finally, our survey will simultaneously observe the CO and [CI] intensity fluctuations arising from z ? 2.5 galaxies, giving the spatial distribution and abundance of molecular gas at cosmic noon. We will measure the amount of molecular gas, its distribution in the cosmic web, as well as its physical conditions and excitation properties, which are essential in our understanding of galaxy evolution. On this topic, immediate results are guaranteed.




Ultra-diffuse galaxies (UDGs) are extreme low-surface brightness (LSB) galaxies (?g ? 24 mag/arcsec^2) with a size of several kpc, up to that of the Milky Way, with at least 100 times smaller stellar masses. Despite the increasing number of studies on UDGs, mainly on imaging data, their observed structural properties do not fit in a single formation scenario. Therefore, questions are still open regarding their formation processes and dark matter (DM) content. We propose a large project to obtain the first homogeneous integral-field spectroscopic survey of UDGs in a cluster environment with MUSE. The target is the Hydra I cluster, at ~50Mpc, where a complete sample of UDG candidates, made by 32 objects in total, have been recently discovered inside 0.6 virial radius of the cluster. With the MUSE data we will confirm their cluster membership, measure their stellar kinematics and stellar populations. The stellar population properties (ages and metallicity) together with the baryonic versus DM fraction will be used in comparison with hydrodynamical models of UDGs to establish their formation channels as a function of their location in the cluster. The MUSE data will also establish the GC population and their specific frequency within 1.5Re for each UDG. This will provide an independent handle on the DM content in these systems. To date, due to their LSB nature, similar studies are available only for about 20 UDGs in total, mainly in the Coma cluster, and only few UDGs have integral-field spectroscopy. By doubling the number of spectroscopically studied UDGs and obtaining a homogeneous survey of these extreme LSB galaxies in the Hydra I cluster, the LEWIS project aims at addressing the open actively debated issues on the UDG nature and formation in a cluster environment.




A handful of planets have recently been revealed residing deep inside the hot Neptunian desert, a region of parameter space devoid of planets due to photoevaporation and tidal interactions. The source of the growing population of in-desert planets is still unsolved, and questions remain over the typical internal properties of close-in planets more widely. The intense irradiation in the desert simplifies internal structure modelling, reducing degeneracies and allowing the planetary core mass, heavy element budget, and rock/ice mass fraction to be determined, all critical parameters for understanding a planet's formation and migration history. We propose to precisely measure the masses and bulk densities of ~30 planets in the Neptunian desert by targeting bright candidates from the TESS photometric survey which are vetted with follow-up photometry and spectroscopy. This will substantially increase the sample of highly irradiated planets with precisely measured masses. Our targets span the range from terrestrial to gas-rich planets, allowing precise comparative planetology by providing a sample of planet masses and bulk densities measured in a uniform fashion across the breadth of the desert. The resulting total of ~80 in-desert planets, with masses measured to at least 20% precision, will allow an in-depth investigation into the origin of these planets and directly reveal the distribution of ice-mass and heavy element fractions of close-in planets in the desert for the first time. All of our targets have had independent followup of their planetary transit made from the ground, in combination with low-resolution spectroscopy and high resolution imaging ruling out the most significant false positive scenarios. The hot Neptunes we will characterise represent ideal targets for atmospheric characterisation with JWST, bridging the gap between the hot Jupiter and terrestrial planet regimes of composition and circulation.




Thanks to a new generation of wide-field sky surveys, some monitoring the sky several times per night, we are now in a golden era of transient astronomy. Gathering the ESO community working on supernovae (SNe), gamma-ray bursts (GRBs) and nuclear transients into one coherent team allows for a revolution in the exploitation of these surveys. Developing efficient synergies with multi-messenger experiments and exoplanet survey satellites makes the NTT a crucial global facility for transient astronomy (100+ papers with NTT data in recent years). NTT spectroscopic surveys have provided legacy datasets for the electromagnetic counterpart of gravitational waves, the lowest metallicity supernovae, the fastest evolving transients, long-lived supernovae not explained by standard neutrino-driven explosions, unveiled a diversity in the most luminous supernovae, as well as probing the observational diversity of the tidal disruption events. We now propose to continue such spectroscopic follow-up, building on the success, experience and efficiency of what done so far and bridging the gap to the SOXS instrument that will arrive at the NTT in 2022 (commissioning) and commence scientific operations in 2023. We will make all reduced data public as done by previous NTT spectroscopic surveys.




Multimessenger astronomy, the detection of an astrophysical source in more than one ``messenger'' (photons, gravitational waves, neutrinos), offers an entirely new way to study the Universe. The first detection of gravitational waves combined with electromagnetic radiation from the merger of a binary neutron star in August 2017 marks the start of a new era in which information about the behaviour of mass from gravitational waves are coupled with constraints on the transfer and release of energy from electromagnetic light. ESO facilities played a pivotal role in the counterpart's discovery and characterisation, delivering spectacular photometric and spectroscopic sequences with great diagnostic power. Here we propose a comprehensive programme of X-shooter, FORS, HAWK-I and MUSE imaging, spectroscopic and polarimetric observations of new electromagnetic counterparts found during the year-long O4 campaign of LIGO/Virgo (start mid-2022). These observations will determine, in detail, the make-up of material ejected in the mergers testing if merging binaries create some, most or all of the heaviest elements seen in nature. They will dissect the physics of the explosion, measuring its geometry and the contribution of fast and slow ejecta. They will measure redshifts and independent electromagnetic distances, enhancing the science return for fundamental physics and cosmology.



van de Sande

Due to the complexity of internal and external processes acting on disk galaxies, many outstanding questions regarding their evolution remain. Our Milky Way provides an unparalleled view of disk evolution, revealing a complex history of minor accretion coupled with internal processes. However, building a comprehensive framework of galaxy evolution from a single object is unrealistic. Instead, we propose to extend Galactic methods to the wider galaxy population, reaping the benefits of detailed Milky Way studies, while probing the diverse mechanisms of galaxy evolution. Edge-on galaxies are ideal for this task: they allow us to disentangle the assembly history imprinted in thick disks and provide the greatest insights into outflows. We propose the GECKOS (Generalising Edge-on galaxies and their Chemical bimodalities, Kinematics, and Outflows out to Solar environments) survey: a representative sample of 35 edge-on galaxies with MUSE, going out to larger radius, deeper (S/N>40 at ? = 23.5 mag/arcsec^2), and with higher spatial resolution (<200 pc) than existing IFS nearby galaxy surveys. Extensive vertical and radial coverage is essential for detecting imprints of minor accretion and outflows. GECKOS will deliver 2D measurements of stellar abundance, age, and kinematics, as well as ionised gas metallicities, ionisation parameters, and outflow kinematics; all core ingredients for chemical evolution models. Our program is optimally designed to determine the assembly histories and properties of galaxies across a large range of SFRs, B/T ratios, and boxy and non-boxy bulges. GECKOS is transformative in two ways: (1) it moves deep studies of edge-on galaxies from single objects to controlled samples, enabling a census of physical properties, and (2) it allows us to apply the chemical evolution models designed for the Milky Way to a range of galaxies. With GECKOS, we will reveal the variation in key physical processes that govern the assembly and evolution of disk galaxies.




We propose MAUVE (MUSE and ALMA Unveiling the Virgo Environment), a large MUSE program designed to shed light on the obscure evolution of the inner discs of cluster galaxies, which typically still host significant cold gas reservoirs after their first pericentre passage, and reveal how star formation ceases in these systems. We will map the full extent of the molecular gas disc (as traced by ALMA observations already at hand) of 40 late-type Virgo cluster galaxies at various infall stages using MUSE. These data will provide stellar and ionised gas kinematics and distributions, star-formation rates, and metal enrichment maps at ~100-200 pc scale, allowing us to investigate the link between cold gas and star formation when and where environmental processes are at play, and as a function of infall time. We will reconstruct detailed star-formation histories for a representative sample of cluster galaxies for the first time, assess the role and impact of outflows, and deliver a rich multi-wavelength data set with a huge legacy value for environmental studies, which no other sample currently available can provide.




This proposal aims at confirming exceptional habitable-zone (HZ) Super-Earth candidates orbiting bright nearby Sun-like stars. Our team has recently re-analyzed all the HARPS archival data using a new tool that allows to correct for instrumental, stellar and telluric systematics and delivers radial-velocities (RVs) that are on average 30% more precise. We then searched for new planetary signals using a novel, more robust, optimal detection criterion, which lead to the detection of a dozen of planetary candidates including 5 HZ Super-Earths. Such planets orbiting bright nearby Sun-like stars (< 15pc and > 0.5 solar masses) are extremely difficult to detect, because the transit, astrometry, microlensing and direct imaging detection techniques are not sensitive to them. However, finding such planets is crucial as they would be the best targets for future missions aiming at characterizing the atmosphere of Earth-like planets through reflected light. Such planets can only be found and confirmed using the RV method in the near future, by following-up promising candidates in RV blind-search surveys. We propose here to follow-up the 5 HZ Super-Earth candidates found in our re-analysis with the HARPS spectrograph. HARPS is preferred over ESPRESSO as the amount of time requested to confirm these long-period, small amplitude planetary signals would be very difficult to schedule on ESPRESSO, and because our realistic simulations show that HARPS precision is good enough. Currently, there is at most only one Super-Earth in the HZ of a nearby Sun-like star (tau cet e) and this detection is strongly call into question by our analysis. We estimate that our program should confirm 3.6 � 0.9 HZ Super-Earths, which would open new perspectives for the field of exoplanets. The 340 hours of time requested to follow-up 5 targets seems huge, however, this is the only way we can confirm such exceptional targets in the near future.




High-fidelity spectroscopy and high-precision radial velocities are an essential technique to obtain accurate planetary masses, radii and densities, while also enabling for the atmospheric characterization of these planets. We pursue one of the main science goals of the ESPRESSO GTO: the detection and characterization of Earth-mass planets (possibly) inside the habitable zone of G, K and M stars. We address it with 3 sub-programs: (1) An intensive search for habitable rocky planets in a sample of the most suitable stars ? some of which already hosting planets ? in the solar neighbourhood. (2) A survey for exoplanetary atmospheres through transit and reflected-light spectroscopy, exploiting the unique spectroscopic capabilities of ESPRESSO and the collecting area of the UTs. (3) A follow-up of the most challenging, low-mass planetary candidates from K2 and TESS missions to obtain their precise densities. This proposal covers the fourth year of ESPRESSO GTO (exoplanetary case).




A big surprise in exoplanet science is the enormous diversity in planetary systems, showing that our Solar-System is just one of the many outcomes of planet formation. The mechanisms that drive this diversity are largely unknown. Planetary systems with gas giants at large orbital separation (>50 AU) are particularly difficult to reconcile with formation theory. With masses straddling the planet/brown-dwarf boundary, in situ formation of these Super-Jupiters could imply disk instability or turbulent fragmentation mechanisms. Understanding how they are linked to free-floating planets and brown dwarfs is therefore critical in this respect. Alternatively, planet-scattering could have catapulted them to their current location, causing other planets to migrate inwards - a crucial ingredient for understanding system architectures. An important avenue to tackle these issues is to determine the chemical characteristics of planet atmospheres and link them to their formation location and evolutionary pathways. The carbon-to-oxygen (C/O) ratio in a planet atmosphere is likely linked to molecular snow lines in protoplanetary disks. In addition, metal-to-hydrogen ratios are expected to depend on formation processes. Most recently, the first isotope ratios have been measured in exoplanet atmospheres (Zhang et al. Nature 2021; Line et al. Nature 2022), with a surprising enrichment in carbon-13 that may be linked to Super-Jupiter formation beyond the CO snow line. Here we propose the ESO SupJup Survey to most optimally make use of these recent developments and target a diverse sample of Super-Jupiters, free-floating planets and brown dwarfs. High-dispersion spectroscopy in J and K-band using the new CRIRES+ will robustly determine the formation-tracers and fundamental parameters in multiple, independent ways. It will determine to what extent these classes of object are really chemically different, and disentangle their formation processes.




The question of the formation of massive stars, and massive binary stars in particular is still very open. Given that recent evidence shows that more than 90%, and perhaps all, of high-mass main sequence stars are found in binary systems, the issue of massive binary formation has gained a lot of interest. This has become even more important as in 70% of the binaries, the stars are close enough to be affected by their companion. Indeed, such close massive binaries are responsible for some of the most energetic phenomena in the Universe. In order to understand massive stars and their evolution it is therefore essential to find out how they formed in multiple systems and how these primordial binaries evolve into the Main Sequence systems observed. To do this, we need to study these stars in the early phases of their evolution. However, data on young massive binary systems is very sparse and we are involved in a project to determine the binarity of young massive stars at all scales. This Large Programme is concerned with binaries at separations between 2 - 100s of au, which can only be probed by optical/near-infrared interferometry. The data will immediately confirm whether the reported observed dearth of massive young binary stars compared to their evolved Main Sequence counterparts is real, and provide vital information on the earliest stages of formation.




Gamma-ray bursts (GRBs) are the most violent and luminous explosions known in the universe, and drive ultra-relativistic jets shocking the surrounding medium. The evolution of their broadband SEDs and polarisation offers a unique laboratory for exploring physics under these extreme conditions. Their bright afterglows provide ideal backlights for detailed analysis of gas in their hosts and the intergalactic medium across cosmic time. We propose a multi-faceted, long-term campaign of rapid follow-up bringing together all current users of ESO for GRB observations. The primary goals are: studying short GRBs and their accompanying kilonovae, thought to be produced by compact object binary mergers, and hence key to understanding r-process cosmic chemical evolution; detailed characterisation of early galaxies through spectroscopy of long GRBs at z>~5; identifying and performing novel investigations of the brightest and most exceptional events; and enabling statistical studies of enhanced samples, for example, constraining the evolution of the ionizing escape fraction from massive stars. ESO facilities have a central role, and our coordinated strategy aims to maximise efficiency and science return. The launch of the Chinese/French SVOM satellite in 2023 promises a step change in the rate of well-localised GRBs, and, thanks to its powerful on-board optical telescope, our ability to identify high priority targets. At the same time, new spectrographs on 2.5-4m telescopes (SOXS at the NTT and NTE at the NOT) will take the strain of obtaining redshifts for more average bursts, while our programme is tailored to complement these developments by exploiting the VLTs for the most challenging and important events.


Last update: OPO - July 18, 2022