Research & Projects

Formation and Evolution of star clusters

Stars do not form in isolation but in clusters composed of a number of siblings ranging from a few tens to several thousands. However, in most cases these clusters dissipate within 10 to 100 Myr, leaving older stars to populate the Galactic field.

I study the mechanisms leading to the formation and the subsequent dissipation of star clusters by analysing their structural and kinematic properties. In particular, I lead and I am involved in several observational studies of nearby young clusters and star forming regions carried out with astrometric data from the ESA space mission Gaia and its associated spectroscopic survey Gaia-ESO. The combined use of these two datasets allowed us to study the dynamical evolution of stellar systems in the 6-dimensional phase space and to unveil the presence within the same regions of multiple substructures. In the next future, I will extend these studies to the youngest regions of the star clusters, which are still embedded in the molecular clouds and are not visible in the optical band.

Color composite image of one of the Orion Nebula Cluster, one of the richest young clusters near the Sun. The image was obtained with the infrared instrument ISAAC at the VLT. Credit: ESO/M. McCaughrean et al. (AIP)

The 4MOST Survey of Young Stars

4MOST is the new multi-object optical spectrograph for the ESO/VISTA telescope, that is currently under construction and will see its first light at the start of 2024. 4MOST will be able to observe simultaneously ~2400 objects distributed over a field of 4.2 square degrees and during the first five years will carry out 18 surveys of stars and galaxies.

I am the Principal Investigator of the 4MOST survey of young stars (4SYS). We will observe about 100,000 young stars within 500 pc of the Sun to measure stellar chemistry, 3D kinematics and ages. These data will be used to: trace the spatial and dynamical evolution of star forming structures as they disperse; quantify the local disk star forming rate and chemical inhomogeneity at a range of spatial scales; vastly expand the numbers of identified young stars for exoplanetary studies; and provide huge coeval samples to improve young stellar evolutionary models.

The Gaia-ESO Survey

Gaia-ESO is a public spectroscopic survey aimed at investigating the formation and evolution of the Milky Way and its stellar population. The survey observed 100,000 stars belonging to the Milky Way components (the disc, the halo, the bulge and open clusters) with the multi-object spectrograph FLAMES at the Very Large Telescope. The astrophysical parameters derived by these observations have been publicly released and in combination with the data from the survey Gaia represent a treasure trove for Galactic Astronomy.

I am one of the builder of the survey and a member of the project office that coordinated the effort to analyse the data and prepare the final release. I have coordinated the team in Arcetri that carried out the data processing for all the high resolution spectra and I have lead and contributed to several papers presenting the scientific results of the survey.

MOONS

MOONS (Multi Object Optical and Near-infrared Spectrograph) is the new multi-object spectrograph for the Very Large Telescope. This instrument which is currently under construction will be able to observe simultaneously up to 1000 targets in the wavelength range between 640 and 1800 nm. The unique capabilities of MOONS combined with the large collective area of the VLT will allow us to investigate the mechanisms driving the evolutions of galaxies across a very large of cosmic times and to study stellar populations in the obscured parts of the Milky Way.

I am part of MOONS Galactic science team. In particular, I am working on a survey of young clusters, that is part of the Galactic survey that will be carried out during 100 nights in the first five years. I am also part of the team that is developing the software to analyse the spectra produced by the Galactic survey and, in particular, I am in charge of the module for the calculation of the stellar radial velocities.

ARIEL

ARIEL (Atmospheric Remote-sensing Infrared Exoplanet Large survey) is a new ESA space mission that will be launched in the 2029 and is aimed at studying the formation and the evolution of exoplanets. ARIEL will observe about 1000 transiting exoplanets in the optical and infrared wavelengths to study the chemical and physical properties of their atmosphere.

I am a member of the ARIEL Science team and of the working group in charge of the characterization of the stars hosting the planets.

Top image Credit: ESO/F. Kamphues

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