In force date
Call year
2017
Investigator
Antonio
Aparicio Juan
Financial institution
Financing subprogram
Amount granted to the IAC Consortium
111.320,00 €
Description
| The main objective of this project is the study of the primeval star formation in nearby systems. In particular, we will address this research in three fundamental types: (1) the Local Group dwarf galaxies; (2) the Milky Way (MW) bulge and old disk populations; and (3) the Milky Way globular clusters. This kind of investigation is mandatory in order to achieve a better understanding of the mechanisms involved in the onset of star formation in the early Universe. The planned research project is very timely for many reasons. The most relevant are: (1) The recent discovery of multiple stellar populations in Galactic globular clusters (GGCs) is challenging our understanding of the mechanisms involved in the formation of these objects, their possible contribution to the formation of the field stellar population of the Galactic halo, and their relation to dwarf galaxies and the missing satellites problem. (2) The availability of space-based observational facilities, like the HST and Gaia, is a basic requirement for an accurate investigation of the stellar content of nearby systems, such as the GGCs, the dwarf galaxies in the Local Group, and the MW itself. (3) The project team has been awarded a large number of HST orbits for observing stellar systems (GGCs and dwarf galaxies) that are key objects in the planned research. To fully reach their potential requires the analysis of available archival data from large, ground-based facilities like the Subaru telescope and the VVV-ESO survey, providing wide-field data of nearby dwarfs and the MW bulge and disk, respectively. (4) Our project team has very recently concluded the upgrade and extension of the BaSTI-IAC stellar evolution library. It provides models for different chemical compositions on demand, that are fundamental for the analysis of the multiple stellar populations in GGCs and for application to the star formation histories (SFHs) in galaxies, all objectives of our research project. The project is organized in four main research lines, whose main objectives are the following: (1) The onset of the star formation in dwarf galaxies: to obtain SFHs of a sample of Local Group dwarf galaxies, to determine with high precision (better than 0.5 Gyr) the onset time of the star formation and to develop a general method to correct the loss of time resolution of the derived SFHs due to observational effects and intrinsic limitations. (2) Stellar populations in the disk and bulge of the Milky Way: to derive the SFH of the edge of the MW bar and Baades window in the bulge, and to extend this derivation to the stellar population of the disk. (3) Multiple stellar populations in Galactic globular clusters: to characterize the properties of the distinct sub-populations present in selected globular clusters, to trace their gradients, to study their He abundances, and to study the stellar mass function and its relation with the mass segregation phenomenon. (4) Enhancement of a stellar evolution library: to extend the new BaSTI-IAC library to account for alpha-enhanced and alpha-depleted heavy elements, to apply the library to the study of the multiple stellar populations in GGCs and the dwarf galaxies stellar populations, and to develop a web interface for the computation of models on-demand, all with varying chemical compositions. |
