1996/08/12 by Dave Strickland, Trevor Ponman, Ian Stevens · 1 citation
Physics and Astronomy · #astro-ph
published as Astron. & Astrophys. 320 (1997) 378-394 · Accepted for publication in Astronomy and Astrophysics. Latex, 23 pages with 12 (of 14) postscript figures. The full paper with all the figures is available at http://www.sr.bham.ac.uk/~dks/M82/m82.html
arxiv created 1996/08/12 · arxiv updated 2009/12/01
We present \em ROSAT PSPC and HRI observations of the galactic wind from the starburst galaxy M82. X-ray emission from the wind is detected to a distance of ∼6\kpc from the plane of the galaxy. Making use of the PSPC's mixture of good spatial and spectral characteristics, we separate point source and diffuse emission, and investigate the spectral variation of the diffuse emission through the wind. The intrinsic X-ray luminosity of the wind in the 0.1-2.4\keV band is found to be approximately 1.9×1040\ergps outside the immediate vicinity of the nucleus. The temperature of the diffuse emission is found to decrease weakly from ∼0.6\keV to ∼0.4\keV along the minor axis, whilst the inferred gas density drops as z-0.5 and z-0.8 along the northern and southern minor axes respectively. We compare these results with those expected from two simple models for the emission: Chevalier & Clegg's adiabatically expanding free wind and emission from shocked clouds in a wind, and find that the emission cannot come from a free wind, but that shock heated clouds could be the source of the emission.