RSAA Colloquia / Seminars / Feast-of-Facts: Friday, 08 September 2017, 14:00-15:00; Duffield Lecture Theatre

Soung-Chul Yang

"Properties of Near-Field Dwarf Galaxies Revealed by their 'Resolved' Stellar Populations"

Prior to the year 2005, the number of known "classical" Milky Way (MW) dwarf satellite galaxies (−8 mag > Mv > −18 mag) remained twelve. However from 2005 to the present, thanks to the high quality photometric data from extremely well designed systematic surveys such as Sloan Digital Sky Survey (SDSS; York et al. 2000) or Dark Energy Survey (DES; Abbot et al. 2005), the number of newly discovered faint dwarf satellites has dramatically increased: Now we have almost forty dwarf satellite galaxies in the halo of the Milky Way (e.g., 15 ultra-faint dwarfs from SDSS; 17 dwarf galaxy candidates from the first two-year data set of DES), and there might be more than tens of faint dwarf satellites still waiting to be discovered in the near future (Koposov et al. 2007; Tollerud et al. 2008). In this talk, I will give a quick guided tour on these near-field dwarf galaxy populations. For in-depth review, we will take a look at several specific case studies on the properties of dwarf satellite galaxies in the Local Group and nearby Sculptor filament. Finally I will close my talk by introducing the usage of "RR Lyrae variable stars" as a versatile probe to "old stellar halos" of nearby galaxies.