EAS Publications Series
Volume 56, 2012The Role of the Disk-Halo Interaction in Galaxy Evolution: Outflow vs. Infall?
|Page(s)||239 - 242|
|Section||Evidence for a Disk-Halo Connection in Galaxies|
|Published online||17 September 2012|
Miguel A. de Avillez (ed)
EAS Publications Series, 56 (2012) 239–242
Unresolved X-ray Emission and Hot ISM in the bulge of M 31
1 Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str.1, 85741 Garching bei München, Germany
2 Space Research Institute, Russian Academy of Sciences, Profsoyuznaya 84/32, 117997 Moscow, Russia
We investigate the unresolved X-ray emission originating from the bulge of M 31. We show that a part of this emission is due to a large number of faint sources – mainly accreting white dwarfs and active binaries, associated with the old stellar population, similar to the Galactic ridge X-ray emission of the Milky Way. We also detect soft X-ray emission from ionized gas. It has a temperature of about ∼300 eV and total mass of ∼2 × 106Msun. The gas distribution is extended along the minor axis of the galaxy suggesting that it may be outflowing in the direction perpendicular to the disk of M 31. The outflow can be maintained from the mass and energy supply from evolved stars and type Ia supernovae respectively.
© EAS, EDP Sciences, 2012