2016 Seminar in Astronomy Space Science Thursday 20

2016 천문우주과학과 세미나 Seminar in Astronomy & Space Science Thursday, 20 Oct 2016 양 성 철 박사 (한국천문연구원) Title : Properties of Near-Field Dwarf Galaxies Revealed by their Stellar Populations 16: 00 PM, 천문우주과학과 세미나실(기 2514호) 천문우주과학과 , BK 21+ 미래우주지질탐사사업단 , 자연과학연구소

ABSTRACT 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. 천문우주과학과 , BK 21+ 미래우주지질탐사사업단 , 자연과학연구 소