In this talk, I will discuss some seemingly unrelated results from different observations of protoplanetary disks. I will mostly focus on our work modelling the SED of disks using an artificial neural network and what we learned by applying this to sources in Taurus. I will then describe our surprising findings when studying the nearby protoplanetary disk MP Mus with ALMA, one of the closest young solar analogues which remained relatively unexplored until recently. Finally, I will propose an alternative (and simpler) explanation for some of the disk azimuthal asymmetries that ALMA has revealed, which can help us better understand their vertical structure. Put together, these observations tell a story that suggests a solution to one of the current main issues in planet formation – only one that we may not like.

Herbig-Haro jets provide a fossil record of the accretion activity of their driving sources. In compact multiple systems this accretion can be regulated by the chaotic motion of the stars. I will give a broad overview of the dynamical processes that lead to the formation of parsec scale jets with particular reference to a new detailed study of perhaps the finest known jet complex, HH 24, based on Subaru, ALMA, HST, and JWST data.  

I will also discuss the importance of high dispersion spectroscopy in the Extremely Large Telescopes (> 30 m) era, focusing on the ANDES instrument at the European ELT, both in terms of refining our understanding of gas giants and pushing towards colder, smaller planets.

The distribution of galaxies in the universe is inhomogeneous, representing large-scale structures (LSS) that consist of galaxy clusters, groups, and the filaments that connect them. Understanding how galaxy characteristics are influenced by their environments and how they evolve over cosmic time within LSS is crucial. Utilizing narrow-band selected emitters, we investigate the environmental effects on star formation within large-scale structures. Utilizing a novel double narrow-band technique, we also explore star-forming activity and the spatial distribution of Hα and continuum emission at z=0.4, probing the cosmic web. We found that star formation in cluster core galaxies is more centrally concentrated and reduced compared to the field sample. We also explore the morphological features and star formation activities of [OII] emitters in the COSMOS UltraDeep field at z ∼ 1.5 using JWST NIRCam data from the COSMOS-Web survey and Subaru Hyper Suprime-Cam. Furthermore, we report the discovery of large filamentary structures traced by [OII] emitters, surrounding an extremely overdense core with a galaxy number density ∼ 11× higher than the field average. Heightened star-forming activity was observed in dense regions, contrary to z=0.4, suggesting an environmental impact on early galaxy evolution. Additionally, we examine the redshift evolution of star-forming activities and morphology. Future studies will explore into the chemical abundance, gas content, and kinematics to comprehend the underlying processes.

Stars of mass below that of the Sun live for sufficiently long that even in ancient systems, star-count techniques can be used to investigate the low-mass stellar Initial Mass Function (IMF). The stars in Ultra-faint dwarf (UFD) satellite galaxies in the Local Group are extremely old and extremely metal-poor and likely formed long ago in an environment very different from that of the local solar neighbourhood.  The inferred dark-matter fraction in these systems is also significantly higher than the values found in larger galaxies. Comparisons between the low-mass IMF in UFD galaxies and that of the local Milky Way thus provides insight into star-formation processes across a range of conditions and redshifts. 

I will describe our recent analyses of deep images from the Hubble Space Telescope for a set of four UFD satellites of the Milky Way plus one UFD that is likely to be a satellite of the LMC.  We conclude that there is little evidence in favour of a variable low-mass IMF. 

The Central Molecular Zone (CMZ) is an extreme environment in the inner few hundred parsecs of the Milky Way Galaxy, with temperatures, pressures, and densities exceeding those measured in the Galactic disk. At a distance of ~8.2 kpc, it has previously been difficult to perform large surveys of the CMZ at high resolution, limiting most studies to individual molecular clouds. ACES (the ALMA CMZ Exploration Survey) is a large ALMA program with high sensitivity observations covering the entire area of the CMZ at high spatial and spectral resolution at 3mm in both continuum and spectral lines. ACES data will be used to determine the overall distribution and chemical composition of mass in the inner Galaxy, from the sub-parsec scales of star formation, to the large-scale global processes that influence it. In addition, spectral line data will be used to create a comprehensive picture of gas kinematics in the CMZ, unveiling how gas flows from galactocentric radii of a few hundred pc down to the vicinity of the central supermassive black hole. Observations and high resolution hydrodynamical simulations will be used in tandem to determine how different physical processes impact the evolution of gas at different scales. We present early science results from the ACES team, including an overview of the data products, the properties of compact sources extracted using ACES continuum data, the rich chemical composition identified in the CMZ, and the characterization of gas kinematics in the CMZ. 

Ultra-diffuse galaxies (UDGs) are extremely low-surface brightness galaxies with a size of several kpc, i.e. comparable to that of the Milky Way, but with at least 100 times smaller stellar masses. In the scope of the LEWIS large programme with VLT-MUSE, we have targeted a complete sample of 32 UDG candidates in the 50-Mpc distant Hydra I cluster. In this talk, I will focus on UDG 32, a galaxy that has been hypothesised to have formed from material stripped from the nearby spiral galaxy NGC 3314a. Our new MUSE data show that NGC 3314a's filaments extend to unprecedented distances, completely engulfing the UDG and confirm that the UDG and the filaments are indeed co-spatial based in position-velocity space. UDG 32 may thus be one of the first ultra-diffuse galaxies where we catch the formation from ram-pressure stripped gas in the act.

High resolution, hydrodynamic galaxy simulations can be used to investigate the inherent variation of dark matter around the Solar Circle of a Milky Way-type galaxy. These simulations self consistently include both the baryonic back-reaction as well as assembly history of substructures, all of which may have lasting impacts on the dark matter’s spatial and velocity distributions, creating `gusts’ of dark matter wind around the Solar Circle, potentially complicating interpretations of direct detection experiments on Earth. Direct detection is a key experimental goal to advance the microscopic understanding of the dark matter that fills the Universe. We investigate how dark matter substructure, simulated in halos analogous to our own Milky Way, impacts the shape, summary statistics, and interpretation of results from terrestrial dark matter direct detectors.

Implementing a new numerical integration technique, our work generates bespoke predictions for terrestrial underground detection, finding large uncertainties arising in the expected signals of direct detection experiments. Having developed a realistic end-to-end pipeline for studying these effects, we discuss the implications of these astrophysical variations in the dark matter distribution of the solar neighbourhood on current and future particle physics searches for dark matter.

On their way from the main sequence to the final supernova explosion, massive stars lose a substantial fraction of their mass through line-driven winds. Recent decades have witnessed significant advancements in both observational and theoretical studies of these winds that sail on starlight. The advancements in our understanding of radiative driving lead to progressively more accurate estimates of mass-loss rates from massive stars. In this talk, we will outline the key ingredients necessary for reliable predictions of mass-loss rates from numerical simulations, and demonstrate how state-of-the-art theoretical mass-loss rate estimates compare with observational results.

Thanks to the recent deep observations, some massive galaxies are known to stop their star formation even just 1-2 Gyrs from the Big Bang. These early massive quiescent galaxies are likely to have obtained their stellar mass by bursty star formation within a short period and suddenly got quenched. However, their statistical properties and quenching mechanisms are still unclear. In this talk, I will introduce our recent studies to characterize massive quiescent galaxies using data from ground-based and space telescopes. 

In the first part of this talk, I will present the result of characterizing the morphology of quiescent galaxies at z>3 using the high-resolution imaging of JWST/NIRCam. We derived their sizes and Sérsic index of ~30 quiescent galaxies. For the first time, we have shown that the size is larger for more massive quiescent galaxies at z>3, as seen at z<3. Their typical sizes are ~0.6kpc at Mstar~5x10^10Msun, smaller than that at z<3; thus, significant size evolution occurred for quiescent galaxies over the last 10 Gyrs.

In the second part of this talk, I will present our study investigating the connection between quenching and AGNs at z~3-5. Using the Chandra data and the multi-band photometry of the ground-based telescopes, we conduct the stacking analysis of X-ray images of ~500 quiescent galaxies. For the first time, we detected the average X-ray emission of quiescent galaxies at z~3-5 and found that they typically have low-luminosity AGNs. Their X-ray luminosity is higher than that of star-forming galaxies, suggesting the possible connection between AGNs and quenching. Also, I will introduce our ongoing work on the detailed characterization of X-ray-detected quiescent galaxies at z~2.

The stars evolving through the asymptotic giant branch (AGB) are generally regarded as highly efficient dust manufactures, owing to the thermodynamic properties of their wind, which prove extremely favourable to the condensation process of gas molecules into solid grains. In this review I will describe the dust and mineralogy of the dust  formed in the surroundings of this class of stars, outlining the role of mass and metallicity, and the importance of these studies for the characterization of evolved stellar populations in galaxies. The contribution from the analysis of the spectral energy distribution of post-AGB stars towards a better understanding of the dust formation process by AGB stars will be also commented on.

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.