Giovedì 15 settembre alle ore 15:00, la Dr. Marina Rejkuba dell’European Southern Observatory, Garching bei München, Germania, terrà il web-seminar dal titolo: Unravelling the formation history of the nearest giant elliptical galaxy.
NGC 5128, sometimes better known by its radio source name as Centaurus A or Cen A, is the nearest giant elliptical galaxy. At a distance of only ~4 Mpc it offers the unique opportunity for the “ELT science”: the study of resolved stellar populations in giant elliptical galaxies. With deep HST imaging we have resolved its individual stars as faint as the core helium burning red clump giants, which provided constraints for metallicity and age distribution of halo stars. The pencil beam imaging across 29 HST pointings across the halo of NGC 5128 enabled measurements of the structural properties as well as stellar population gradients extending out to 140 kpc projected distance from its centre. I will present the results of the studies of the extended stellar halo of NGC 5128, give an overview of two main formation scenarios that are discussed in the literature and at the end provide an outlook for future studies.