I will present recent results from the mm-Wave Interferometric Survey of Dark Object Masses (WISDOM), a high resolution survey of molecular gas in galaxy nuclei. First, I will show that CO can be used to easily and accurately measure the masses of the supermassive black holes (SMBHs) lurking at galaxy centres. In particular, I will highlight the latest measurements, that spatially resolve the SMBHs’ spheres of influence with a few tens of resolution elements, thus leading to very precise measurements. Second, I will introduce SMBH mass-independent metrics to compare molecular gas and megamaser measurements. In turn, I will show that molecular gas observations now probe the same region of the SMBHs’ neighbourhoods, and that the mass measurements are now equally competitive. Third, if time allows, I will introduce the newly-discovered "mm fundamental plane of black hole accretion", that is surprisingly tight and holds for a wide variety of active galactic nuclei and stellar-mass black holes. This work opens the way to both precise and numerous SMBH mass measurements across the Hubble sequence (in both active and non-active galaxies) with a unique method, and thus promises to revolutionise our understanding of the co-evolution of galaxies and black holes.

In 2021 a young, solar type star underwent a complex series of eclipsing events that lasted over 900 days, preceeded by an infrared brightening seen in NEOWISE photometry some 1000 days prior to the optical eclipse. We propose that this is evidence for a collision event between an ice giant exoplanets and another exoplanet in the system, forming a luminous remnant called a `synestia’ surrounded by an expanding and cooling cloud of debris that caused the later optical eclipse. We show that Cycle 3 JWST spectroscopy will be able to confirm our models for the glowing remnant and surrounding cooler dust cloud, and discuss the implications for planet formation and evolution.

Stellar-mass black holes (BHs) are unique objects to constrain stellar and star cluster initial conditions and evolution, as they encode valuable information on their short-lived progenitor stars. If a significant fraction of BHs receive negligible natal kicks at birth, they can be retained even in open clusters with low escape velocities.

In this talk, I will present the first search for BHs in the closest open cluster to the Sun, the Hyades. I will show that the exquisite measurements by Gaia, combined with accurate N-body models, now give us the opportunity to infer signatures of even few BHs in open clusters, from the imprints they leave on the cluster’s stellar populations. For the Hyades, the observations are best reproduced by models with 2-3 BHs at present, while those that have never possessed BHs cannot match the cluster mass and size simultaneously. I will discuss how this result can provide key information on the BH natal kick distribution, one of the most crucial but still unconstrained aspects of BH formation.

Moreover, I will characterize the populations of BH-star binaries in open clusters. I will explore possible candidate stars with a BH companion in the Hyades, based on their excess error in the Gaia single-source catalog but high membership probability. Finally, I will investigate if dynamical interactions in young and open clusters can trigger the formation of Gaia BHs.

Future and ongoing infrared and radio observatories such as JWST, METIS, and ALMA will increase the amount of rest-frame IR spectroscopic data for galaxies by several orders of magnitude. While studies of the chemical composition of the interstellar medium (ISM) based on optical observations have been widely spread over decades for star-forming galaxies (SFGs) and, more recently, for active galactic nuclei (AGN), similar studies need to be performed using IR data. In the case of AGN, this regime can be especially useful given that it is less affected by temperature and dust extinction, traces higher ionic species, and can also provide robust estimations of the chemical abundance ratio N/O. Moreover, regarding (Ultra)-Luminous Infrared Galaxies ([U]LIRGs), the IR regime peers through their dusty medium and allow us to include the obscured metals in their studies. In this contribution, I will provide a summary of the bayesian-like code HII-CHI-Mistry-IR, which takes advantage of photoionization models, characterized by the chemical abundance ratios O/H and N/O, and the ionization parameter U, to compare their predicted emission-line fluxes with a set of observed values. Instead of matching single emission lines, the code uses some specific emission-line ratios that are sensitive to the above free parameters. I will also review our most recent findings from the study of IR emissions, starting from the performance of the code and its comparison to optical studies, following by a discussion on the universality of the S/O chemical abundance ratio, which can be independently estimate thanks to the set of emission lines available in this regime, and ending up by the finding of deviations from the mass-metallicity relation (MZR) as a consequence of the action of massive inflows of metal poor gas that produces that some galaxies experience a "deep-diving" phase in the MZR diagram as the metals from their ISM are diluted. 

HARPS is one of the most long-lived and proficient instruments installed at ESO telescopes. During 20 years of operation, it has produced about 800 thousand spectra, half of them of astrophysical sources and the other half of the Sun. These observations have been of paramount importance in advancing the understanding of stellar phenomena and discovery of exoplanets.

A first critical review of the observations of astrophysical sources was published in the ESO Archive as HARPS Radial Velocity catalog. This allows archive users to access the radial velocity of the targets and identify the spectral types observed, expanding the RV content using the Halpha line for RV determination.

In this talk, I will discuss the process of associating these observations with SIMBAD identifiers, a key step in cataloging and analyzing this vast dataset, and I will show how the resulting HR diagram from the HARPS RV catalog facilitates the identification of stars based on their physical characteristics.

I will also present the plan for producing a high-resolution high signal-to-noise stellar library and offer some insights into the chemical/physical and temporal characterization of this dataset.

The activity of the Sun and solar-like stars is driven by a dynamo mechanism, according to which the combination of differential rotation and convective motions of the outer atmospheric envelope continuously regenerates the magnetic field that manifests itself in the form of powerful optical, UV, and X-ray radiation. M-L dwarfs are also known to be magnetically active, but the physical mechanism is poorly understood. Studying their X-ray emission and its variability with rotation and stellar parameters allows to constrain the dynamo mechanism that powers the magnetic field and causes activity in the atmosphere.

In this talk, I present our attempt on constraining the magnetic dynamo of M dwarfs by studying the mass-dependent activity-rotation relation for the largest and most uniform sample of M dwarfs with observations taken with XMM-Newton, Chandra, eROSITA, K2 and TESS combined with X-ray and rotation data from the literature. Finally, I will present the relation between the X-ray and radio luminosity of ultracool dwarfs, and the evidences of a previously proposed bimodal dynamo responsible for the magnetic activity of these objects.

Where and how stars form within galaxies are two of the most critical questions in galaxy evolution. Our understanding of the star formation process is limited, ultimately, by our understanding of the sites of individual star formation — giant molecular clouds (GMCs). These dense, gaseous structures have sizes of 10s of pc, so the high spatial resolution required to resolve them has been mostly unattainable beyond the Local Group before the advent of the ALMA interferometer. Even then, acquiring the statistical sample of these ‘cloud-scale’ observations to answer questions like how local environment (bars, rings, etc.) module the star formation process has been an undertaking requiring 100s of hours of observing time with dedicated teams.

I will present some new results from the mm-Wave Interferometric Survey of Dark Object Masses (WISDOM) project looking at the properties of molecular clouds in ‘red and dead’ early-type galaxies, attempting to understand why these often molecular gas-rich galaxies do not form stars. We find that the molecular gas in these galaxies is often not in virial equlibrium, and external forces such as shear are likely destroying the clouds on shorter timescales than required for star formation to occur. The gas in these galaxies may be analogous to those in the Central Molecular Zone (CMZ) of the Milky Way, and provide an excellent laboratory for studying the interaction between extreme dynamics and cloud-scale properties. Combining ALMA with MUSE optical inteferometry, I have also been studying star formation on a resolved level in these quiescent galaxies. Star formation appears to be extremely localised to very small regions of the galaxy, and our integrated star formation rate measurements may be severely biased by this, with the true SFR being maybe an order of magnitude lower. However, resolved star formation efficiencies are similar to that of star forming galaxies, indicating that when star formation does happen, it perhaps happens in the same way across the galaxy population. 

The DSA-2000 will be a world-leading radio survey telescope and multi-messenger discovery engine, commencing construction in 2025. Building on proven technology developed for DSA-110, the array will consist of 2000 x 5m dishes instantaneously covering the 0.7-2 GHz frequency range, spanning an area of 19 km x 15 km in Nevada. In an initial five-year survey, the DSA-2000 will image ~33,000 deg2 repeatedly over sixteen epochs, producing a combined full-Stokes sky map with 500 nJy/beam rms noise and 3.3 arcsecond spatial resolution. Fundamental questions surrounding the baryon cycle in galaxies, the formation of stars over cosmic time, and the influence of active SMBHs on galaxies, will be addressed by detecting over a billion star-forming galaxies and active SMBHs, and by observing the neutral-hydrogen kinematics and contents of several million galaxies. The array will revolutionize the field of radio transients, detecting >10,000 FRBs, >10,000 pulsars and >1 million slow transients, with sub-arcsecond localization for host galaxy identification. The DSA-2000 will also be a leading instrument for the discovery and characterization of the electromagnetic counterparts to neutron-star mergers found by ground-based GW detectors. Overall, it will thus also serve as the radio counterpart of the Rubin-LSST survey.

ALMA has embarked upon a 150 million Euro upgrade, the so-called “Wideband Sensitivity Upgrade” or WSU, that is currently planned to be commissioned and ready for use around the end of this decade. In this talk I will outline what this upgrade means both in practical terms and for new capabilities. This is a truly massive upgrade, with essentially only the ALMA antennas staying the same. All other parts of the signal chain  - receiver bands, digitizers, data transmission system, over 40 km of optical fibres, correlator – will be replaced or upgraded to give a system with x2 to x4 increase in instantaneous bandwidth. The WSU upgrade will result in a factor of 3-6 increase in continuum mapping speed and a factor of 2-3 increase in spectral line imaging speed. Importantly, ALMA users will no longer need to sacrifice bandwidth in order to work at high velocity resolution (e.g., 0.1 km/s). For ALMA operations, a major change will be that the ALMA correlators, which are currently at >5 km altitude, will be replaced by a correlator at the ALMA Base Camp (Operations Support Facility at 3 km altitude). To meet the challenges of this era of intensive ALMA Development, for ALMA 2030 and beyond, the ESO ALMA Support Centre (EASC) has recently created a new department for Development. In this talk I will describe the new EASC structure and other ways that the EASC is stepping up to the delivery of this - in essence - brand new ALMA.

The masses of the supermassive black holes in AGNs can be determined by resolving the BH sphere of influence in time via reverberation mapping (RM). The resulting relationship between the broad-line region (BLR) radius and AGN luminosity serves as a baseline for measuring black hole mass (MBH) across the entire Universe.  For an increasing number of nearby AGNs, time-costly high signal-to-noise and high cadence RM data provide insights into BLR geometry and kinematics, offering independent MBH measurements. In combination with spatially-resolved measurements of the host galaxy kinematics, this enables us to constrain the MBH-host galaxy scaling relations with unprecedented resolution. In this talk, I will present the calibration of the MBH-stellar-velocity-dispersion relation for a sample of AGNs with velocity-resolved lags from the BLR. I will discuss the biases introduced by different aperture sizes, host galaxy morphologies, and AGN luminosities, along with the consequences for interpreting such scaling relations as tests for the black hole - host galaxy co-evolution.

The SPECULOOS (Search for habitable Planets EClipsing ULtra-cOOl Stars) project aims to perform a transit search on the nearest (< 40 pc) ultracool (<3000K) dwarf stars. The project is based on a network of 1m robotic telescopes, composed by the four ones of the SPECULOOS-Southern Observatory (SSO) in Cerro Paranal, Chile, one telescope of the SPECULOOS-Northern Observatory (SNO) in Tenerife, and the SAINTEx telescope in San Pedro Martir, Mexico. The prototype survey of the SPECULOOS project on the 60 cm TRAPPIST telescope (Chile) discovered the TRAPPIST-1 system, composed of seven temperate Earth-sized planets orbiting a nearby (12 pc) Jupiter-sized star. The project's main motivation is to discover potentially habitable planets well-suited for detailed atmospheric characterisation with James Webb Space Telescope (JWST) and the upcoming giant telescopes, like the European Large Telescope (ELT). Beside conducting observations of targets from the SPECULOOS input catalog, a fraction of the available observing time of the SPECULOOS network is used to carry out different science goals, the so-called annex programs. I will present an overview of the project, our observation strategy and the management and operations of our facilities. Finally, I will show the latest results of the survey and the synergy of our programs with the Transiting Exoplanet Survey Satellite (TESS) and JWST.

Multiple populations distinguishable by their light-element content are well studied in many globular clusters (GCs). Additionally iron spreads have been measured in some of them. In this talk an analytical method to determine the number of core collapse supernovae (CCSNe) that must have contributed to this iron spread is presented. From this the duration of star formation during the initial stage of a GC’s development can be computed. For a sample of 55 GCs with known iron spreads we find that the number of CCSNe required to explain the iron spread varies between a few tens of thousands and a few. In most cases, however, this leads to a SF duration typically around 3.5 Myr.

Przybylski's star is probably one of the most unique stars of our Galaxy. Its spectrum is overloaded with lines of s-process elements. Quantitative analysis shows that the overabundance of these elements in the Przybylski's star atmosphere is enormous. The reason for this is unknown. I will briefly discuss new ideas that may help to better understand this mysterious star and its chemical anomalies.

I will discuss recent advances in the understanding of globular star clusters from combining space-based data (Gaia parallaxes and proper motions, HST photometry) with data from large ground-based telescopes like the VLT. I will in particular discuss the initial mass function of globular clusters, the evolution of their black hole population and the possible presence of dark matter in globular clusters.