The search for the sub-solar initial mass function in the Local Group

Abstract

The stellar Initial Mass Function (IMF) is a quantity which accounts for the distribution of the masses of stars, when they are formed. All the information available on the IMF in the low-mass regime comes from studies of our galaxy alone. Investigations on the content of low-mass stars in other neighbouring galaxies are limited by observational constraints, which do not allow the detection of the fainter stars with statistical significance. Only recently results from observations with the Hubble Space Telescope (HST) of stellar populations in the Large Magellanic Cloud (LMC) down to $\sim$ 0.7 M$_\odot$ confirm systematic variations in the low-mass IMF expected from theoretical considerations (Gouliermis et al. 2005). Direct imaging of resolved stellar populations in massive young clusters throughout the Local Group would be possible with Extremely Large Telescopes (ELTs). Hence, a sizeable sample of young clusters for which IMF variations can be detected would become available. We present our method for testing the efficiency of observations with ELTs in detecting low-mass stars in compact clusters of the Local Group galaxies. We plan to simulate imaging with ELTs and use the results of their photometry in order to investigate the effect on the derived low-mass IMF. This method demonstrates the advantages that will be introduced to crowded field photometry in close-by galaxies with ELTs.