2008/02/26 by Manuel Metz, Pavel Kroupa, Noam I. Libeskind · 6 citations
Physics and Astronomy · #Astronomy #Astrophysics #Cosmology and Gravitation Theories #Dark matter #Dwarf galaxy problem #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy formation and evolution #Galaxy group #Local Group #Milky Way #Orbital elements #Physics #Population #Satellite #Satellite galaxy #Scientific Research and Discoveries #astro-ph
paper · pdf · doi:10.1086/587833
Accepted for publication in ApJ
arxiv created 2008/02/26 · openalex publication_date 2008/06/06 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We use available proper-motion measurements of Milky Way (MW) satellite galaxies to calculate their orbital poles and projected uncertainties. These are compared with a set of recent cold dark matter (CDM) simulations tailored specifically to solve the MW satellite problem. We show that the CDM satellite orbital poles are fully consistent with being drawn from a random distribution, while the MW satellite orbital poles indicate that the "disk of satellites" of the Milky Way is rotationally supported. Furthermore, a bootstrap analysis of the spatial distribution of theoretical CDM satellites also shows that they are consistent with being randomly drawn. The theoretical CDM satellite population thus shows a significantly different orbital and spatial distribution from that of the MW satellites, most probably indicating that the majority of the latter are of tidal origin rather than being dark matter-dominated substructures. A statistic is presented that can be used to test a possible correlation of satellite galaxy orbits with their spatial distribution.