2005/01/31 by J. An, J. H. an, N. W. Evans · 6 citations
Physics and Astronomy · #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #Scientific Research and Discoveries #astro-ph
paper · pdf · doi:10.1086/499305
published as Astron.J. 131 (2006) 782-789 · to appear in AJ, extended appendix, typo corrected from the 2nd version (completely rewritten from the 1st version, see also astro-ph/0508419 for some materials split from the 1st version)
arxiv created 2005/12/30 · openalex publication_date 2006/01/24 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
This paper provides two families of flexible and simple galaxy models. Many representatives of these families possess important cosmological cusps, with the density behaving like r -1 , r -4/3 , or r -3/2 at small radii. The density falls off between r -3 and r -5 at large radii. We provide analytic and anisotropic distribution functions for all the models. Unlike many existing methods, our algorithm can yield tangentially anisotropic velocity dispersions in the outer parts, and so is useful for modeling populations of satellite galaxies and substructure in host galaxy halos. As an application, we demonstrate the degeneracy between mass and anisotropy for the satellite galaxy population of the Milky Way. This can introduce a factor of ∼3 uncertainty in the mass of the Milky Way as inferred from the kinematics of the satellite population.