Affiliation:
1. Special Astrophysical Observatory, Nizhniy Arkhyz, Karachai-Cherkessia 369167, Russia
Abstract
ABSTRACT
Using our Hubble Space Telescope/Advanced Camera for Surveys (HST/ACS) observations of the recently found isolated dwarf spheroidal (dSph) galaxies, we homogeneously measured their star formation histories (SFHs). We determined SF rate as a function of time, as well as age and metallicity of the stellar populations. All objects demonstrate complex SFH, with a significant portion of stars formed 10–13 Gyr ago. Nevertheless, stars of middle ages (1–8 Gyr) are presented. In order to understand how the SF parameters influence the evolution of dSphs, we also studied a sample of nearest dSphs in different environment: isolated (d < 2 Mpc); beyond the Local Group (LG) virial radius (but within the LG zero-velocity sphere); and the satellites of M 31 located within the virial zone (300 kpc). Using archival HST/ACS observations, we measured their SFHs. A comparative analysis of the parameters obtained allow us to distinguish a possible effect of the spatial segregation on the dSphs evolution scenario.
Funder
Smithsonian Astrophysical Observatory
National Aeronautics and Space Administration
Entomological Society of America
Space Telescope Science Institute
Publisher
Oxford University Press (OUP)
Subject
Space and Planetary Science,Astronomy and Astrophysics
Cited by
4 articles.
订阅此论文施引文献
订阅此论文施引文献，注册后可以免费订阅5篇论文的施引文献，订阅后可以查看论文全部施引文献