1. Recent Research Progress (Junsup Shim, KIAS)
2. Modelling chemical abundance distributions for giant elliptical galaxies: the comparison with an outer halo field in NGC 5128 (Ena Choi, KIAS/QUC)
Abstract - The stellar metallicity distribution functions (MDF) has been measured for resolved stellar populations in outer halos of many galaxies in nearby groups. Among them, the MDF of NGC 5128, the central giant elliptical in the Centaurus group, provides important constraints for massive galaxy formation and hierarchical assembly models. To investigate the formation and chemical evolution history of outer halo of giant elliptical galaxies, we examine the chemical properties of 3 cosmological hydrodynamical simulations of an NGC 5128-like massive galaxy and compare their MDFs of outer halo field to the observed one of NGC 5128. Even though simulated galaxies have different merging histories and different age distributions, they all show comparable MDFs to the observed one. In this talk, I will discuss the origin of the stellar particles ending up in the outer halo field of massive galaxies. Most of stars in outer fields of galaxies have `accreted' origin, formed in other small galaxies and later merged in. Only 15 % of stars are formed `in-situ' in the central region of the main progenitor of galaxy and radially migrate away.