Diffuse X-ray Emission from M101
Abstract
I present an analysis of the diffuse X-ray emission from the disk of M101 as observed by <i>Chandra</i> and <i>XMM-Newton</i>. The X-ray emission tracks the <i>GALEX</i> FUV emission, thus implying that the X-ray emission is dominated by star-formation. At <i>Chandra/XMM</i> resolution, the diffuse spectrum is dominated by O VII, O VIII, and the Fe-L complex. A 0.75-1.0 keV/0.4-0.75 keV hardness ratio map shows that, with the exception of two giant H II regions, the hardness ratio does not vary significantly across the disk, meaning that a spectrum extracted from the entire disk is, in fact, representative of the spectrum of most smaller regions. The diffuse spectrum is well fit by two thermal components with kT=(0.18,0.65) keV. These temperatures are representative of a number of other late type spiral disks observed by <i>Chandra</i> and <i>XMM-Newton</i>,and are similar to those seen in Galactic star-forming regions. It is not currently clear whether the uniformity is real, or due to the relatively low spectral resolution; simulations suggest that a number of different distributions of emission measure, when observed at this resolution, would produce the fitted values.
- Publication:
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American Astronomical Society Meeting Abstracts #208
- Pub Date:
- June 2006
- Bibcode:
- 2006AAS...208.4922K