Globular clusters in the large magellanic cloud: An impact from GAIA photometry

Abstract

The goal of this work is to assess the expected scientific output from the photometric studies of globular clusters in the Large Magellanic Cloud with ESA’s astrometric space mission GAIA. For this purpose we simulate GAIA photometry of individual stars in synthetic cluster populations, covering a large range of cluster ages and metallicities. We find that accurate effective temperatures (Δ T eff < 10%) can be obtained from GAIA photometry down to V ~ 18 for stars in populations within the studied metallicity range ([M/H] = −0.4 … −1.7). GAIA will also provide photometric metallicities (Δ[M/H] ≲ 0.3 dex) for the cluster giants brighter than V ~ 17.5. The knowledge of the effective temperatures and metallicities will allow to obtain accurate ages of stellar populations younger than about 1 Gyr using the usual procedure of main sequence turn-off point fitting. Ages of older stellar populations (≳ 1 Gyr) may be constrained from the isochrone fits to the giant branches in the observed CMDs. We conclude that GAIA will provide excellent opportunities for studying star formation histories far beyond the Milky Way, providing means for better understanding of stellar and galactic evolution in different astrophysical environments.