Structure and dynamics of the old galactic components

Masashi Chiba, Hirohito Hayashi, Motoko Yamada

Research output: Contribution to journalConference articlepeer-review


We present here the recent progress in our understanding of the old stellar components of the Milky Way as fossil records of galaxy formation. Special attention will be paid to if the Cold Dark Matter (CDM) theory as a current theoretical paradigm is able to reproduce recently accumulated data sets of Galactic stars as provided by extensive surveys such as SDSS. We show our recent studies in this regard. First, we have simulated the dynamical interaction between a stellar disk and numerous CDM subhalos to get insights into the origin of the thin and thick disks. Second, we have analyzed the global dynamics of more than 1600 field horizontal branch stars as halo tracers to probe their velocity distribution inside the dark halo of the Milky Way. A detailed comparison with the CDM predictions has been made and key issues are addressed for understanding the formation of the Milky Way.

Original languageEnglish
Pages (from-to)55-62
Number of pages8
JournalAstrophysics and Space Science Proceedings
Issue number202419
Publication statusPublished - 2008 Jan 1
EventSymposium on Mapping the Galaxy and Nearby Galaxies, 2006 - Ishigaki island, Japan
Duration: 2006 Jun 262006 Jun 30

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Computer Science Applications
  • Spectroscopy
  • Space and Planetary Science
  • Nuclear and High Energy Physics

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