2001/08/17 by Francisco Prada, Andreas Burkert
Physics and Astronomy · #Astronomy and Astrophysical Research #Electrical and Electromagnetic Research #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1086/338979
9 pages,2 figures. Submitted to ApJ Letters
arxiv created 2001/08/17 · openalex publication_date 2002/01/10 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
We present a new correlation between the mass-to-light ( M / L ) ratio and the mean metallicity for the satellites of the Local Group. This relation, together with their central surface brightness, defines a fundamental line where metal-poor and low surface brightness dwarf galaxies are dark matter dominated while metal-rich high surface brightness systems will have a low M / L ratio. This fundamental line is independent of distance to the central galaxy (M31 and the Milky Way) and morphological type, among other global parameters, as their star formation history. The new M / L -metallicity relation indicates that dwarf spheroidal galaxies are dark matter confined and that their high M / L ratios are not a result of the tidal loss of stars. It can be interpreted that these satellites experienced a continuous loss of metals with a final episode of gas ejection at the end of the star formation epoch. Only globular clusters are found to lie outside the fundamental line of dwarf satellites. Unlike satellite galaxies, they are not dark matter confined.