2007/05/31 by M. Spaans, R. Meijerink · 2 citations
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics and Star Formation Studies #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1086/520535
added discussion on more recent X-ray observations
arxiv created 2007/06/02 · openalex publication_date 2007/06/28 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
Based on its strong CO + emission, it is argued that the M82 starburst galaxy is exposed to a combination of FUV and X-ray radiation. The latter is likely to be the result of the starburst superwind, which leads to diffuse thermal emission, and a compact hard source (but not an AGN). Although a photon-dominated region (FUV) component is clearly present in the nucleus of M82, and capable of forming CO + , only X-ray irradiated gas of density 10 3 -10 5 cm -3 can reproduce the large, ~(1-4) × 10 13 cm -2 , columns of CO + that are observed toward the prototypical starburst M82. The total X-ray luminosity produced by M82 is weak, ~10 41 ergs s -1 , but this is sufficient to drive the formation of CO + .