X-ray Emission from the Local Bubble
Abstract
We present here the result of our analysis of two XMM-Newton pointing in the direction of the high density, high latitude, neutral hydrogen cloud MBM-20 and of a nearby low density region that we called the Eridanus Hole. MBM-20 is at a distance evaluated around 100-200 pc from the Sun and its density is sufficiently high to shield about 95% of the foreground emission in the 3/4 keV energy band. This allowed us to have a good estimate of the O VII and O VIII foreground emission due to the Local Bubble. Moreover, the combination of the two observations makes possible an almost independent evaluation of foreground and background emission due primary to the galactic halo. The two observations are in good agreement with each other and can be explained by two plasmas (one absorbed, the other unabsorbed) in thermal equilibrium, without evidence for any strong contamination from ion exchange in the solar system. The total flux in the two observations is compatible with ROSAT observations of the same part of the sky and the comparison of O VII and O VIII line flux from foreground and background gives us an estimated temperature of 1.2E6 K for the unabsorbed component and 2.3E6 K for the absorbed one.
- Publication:
-
AAS/High Energy Astrophysics Division #9
- Pub Date:
- September 2006
- Bibcode:
- 2006HEAD....9.0768U