Globular clusters in early-type dwarf galaxies
One of the main aims of modern astrophysics is to understand the role of dwarf galaxies and their globular cluster (GC) systems as building blocks of massive galaxies. Dwarf spheroidal (dSph) and dwarf elliptical (dE) galaxies reveal unusual properties. Recent studies of dSph galaxies in the Local Group and other nearby groups within 10 Mpc show that these galaxies are composed mainly of old stars, contribute the faintest end of the galaxy luminosity function, are repositories of dark matter and often contain bright globular clusters near their centres. Studying the abundances and colour–magnitude diagrams of GCs in nearby dSph and dE galaxies can shed light on their evolutionary histories. GCs in the early-type satellites of the Andromeda galaxy, NGC 147, NGC 185 and NGC 205, are close enough to be resolved into single stars by the Hubble Space Telescope (HST). We discuss the results of our high-quality HST–WFPC2 photometry of stars in these GCs and the measurements of ages, metallicities and [α/Fe] ratios for these GCs, based on integrated-light spectra obtained with the SCORPIO spectrograph at the 6Âm telescope of the Russian Academy of Sciences.
Document Type: Research Article
Affiliations: 1: Special Astrophysical Observatory, Russian Academy of Sciences, Nizhnii Arkhyz, Karachai-Cherkessian Republic, 369167, Russia 2: Space Telescope Science Institute, 3700 Sun Martin Drive, Baltimore, Maryland, 21218, USA
Publication date: 2006-04-01