2007/03/31 by Nicolas F. Martin, Rodrigo A. Ibata, Mike Irwin · 5 citations
Physics and Astronomy · #Andromeda #Astronomy and Astrophysical Research #Galactic corona #Galactic halo #Galaxies: Formation, Evolution, Phenomena #Halo #Milky Way #Stellar density #Stellar structure #Stellar, planetary, and galactic studies #Young stellar object #astro-ph
paper · pdf · doi:10.1086/522791
accepted for publication in ApJL, 4 pages, 4 figures. Significant changes including a larger dataset and a more thorough discussion
arxiv created 2007/08/31 · openalex publication_date 2007/10/08 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
This Letter reports on the Galactic stellar structures that appear in the foreground of our Canada-France-Hawaii-Telecopse/MegaCam survey of the halo of the Andromeda galaxy. We recover the main sequence and main-sequence turnoff of the Triangulum-Andromeda structure recently found by Majewski and collaborators at a heliocentric distance of ~20 kpc. The survey also reveals another less populated main sequence at fainter magnitudes that could correspond to a more distant stellar structure at ~28 kpc. Both structures are smoothly distributed over the ~76 deg 2 covered by the survey, although the closer one shows an increase in density by a factor of ~2 toward the northwest. The discovery of a stellar structure behind the Triangulum-Andromeda structure that itself appears behind the low-latitude stream that surrounds the Galactic disk gives further evidence that the inner halo of the Milky Way is of a spatially clumpy nature.