1997/11/28 by Ralf S. Klessen, Ralf Klessen, Pavel Kroupa · 124 citations
Physics and Astronomy · #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Dark matter #Dark matter halo #Dwarf galaxy problem #Galaxies: Formation, Evolution, Phenomena #Galaxy #Halo #Milky Way #Physics #Satellite #Satellite galaxy #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/305540
published in The Astrophysical Journal 498(1), 143-155 (IOP Publishing) · MPIA: Max Planck Institute for Astronomy (Heidelberg); ITA: Institute for Theoretical Astrophysics (Heidelberg); 36 pages including 19 figures; accepted for publication in ApJ; also available at http://www.mpia-hd.mpg.de/MPIA/Projects/THEORY/klessen/Preprints/p4.ps (1.8MB)
arxiv created 1997/11/28 · openalex publication_date 1998/05/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Self-consistent simulations of the dynamical evolution of a low-mass satellite galaxy without dark matter are reported. The orbits have eccentricities of 0.41 ≤ e ≤ 0.96 in a Galactic dark halo with a mass of 2.85 × 10 12 M ☉ and 4.5 × 10 11 M ☉ . A particle-mesh code with nested subgrids and a direct-summation N -body code running with the special-purpose hardware device GRAPE are used for the simulations. Initially, the satellite is spherical with an isotropic velocity distribution and a mass of 10 7 M ☉ . Simulations with 1.3 × 10 5 up to 2 × 10 6 satellite particles are performed. The calculations proceed for many orbital periods, until well after the satellite disrupts. In all cases, the dynamical evolution converges to a remnant that contains roughly 1% of the initial satellite mass. The stable remnant results from severe tidal shaping of the initial satellite. To an observer from Earth, these remnants appear strikingly similar to the Galactic dwarf spheroidal satellite galaxies. Their apparent mass-to-light ratios are very large, despite the fact that they contain no dark matter. These computations show that a remnant without dark matter displays larger line-of-sight velocity dispersions, σ, for more eccentric orbits, as a result of projection onto the observational plane. Assuming that they are not dark matter dominated, it follows that the Galactic dSph satellites with σ > 6 km s -1 should have orbital eccentricities of e > 0.5. Some remnants have substructure along the line of sight that may be apparent in the morphology of the horizontal branch.