2008/04/30 by M. Revnivtsev, E. Churazov, S. Sazonov +2 · 1 citation
Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Cosmic Phenomena #Bulge #Elliptical galaxy #Emissivity #Galaxies: Formation, Evolution, Phenomena #Galaxy #Luminosity #Milky Way #Physics #Population #Spiral galaxy #Star formation #Stellar population #astro-ph
paper · pdf · doi:10.1051/0004-6361:200809889
9 pages, 7 figures, Accepted for publication in A&A
arxiv created 2008/06/27 · openalex publication_date 2008/07/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We use deep Chandra observations to measure the emissivity of the unresolved X-ray emission in the elliptical galaxy NGC 3379. After elimination of bright, low-mass X-ray binaries with luminosities 1036 erg s-1, we find that the remaining unresolved X-ray emission is characterized by an emissivity per unit stellar mass 1027 erg s-1 in the 0.5-2 keV energy band. This value is in good agreement with those previosuly determined for the dwarf elliptical galaxy M 32, the bulge of the spiral galaxy M 31 and the Milky Way, as well as with the integrated X-ray emissivity of cataclysmic variables and coronally active binaries in the Solar neighborhood. This strongly suggests that i) the bulk of the unresolved X-ray emission in NGC 3379 is produced by its old stellar population; and ii) the old stellar populations in all galaxies can be characterized by a universal value of X-ray emissivity per unit stellar mass or per unit K band luminosity.