The Three-Dimensional Structure of the Hot Interstellar Medium
Abstract
The diffuse soft X-ray background is primarily of Galactic origin. Million degree gas in both the Local Hot Bubble and the Galactic halo produce the 1/4-keV band emission, while a combination of extragalactic and galactic point sources, and diffuse emission appear to produce the 3/4-keV band emission. While energy-dependent intensity maps provide a wealth of information about the two-dimensional structure of the X-ray emitting material, constraining the distance to the emission is vital towards full understanding of its three-dimensional structure. X-ray shadows provide a means to differentiate foreground and background emitting regions towards absorbing clouds. I present analysis of ROSAT PSPC observations towards ten molecular clouds at a range of Galactic latitudes and distances. Spatial anti-correlation between infrared 100 mu m dust emission, a tracer of the absorbing gas, and the X-ray emission is studied by fitting a single-slab absorption model. The nearest of the clouds are used to confirm the scaling of the Local Hot Bubble presented by Snowden et al. (1998, ApJ, 493, 715). The 1/4-keV band observations towards clouds at high Galactic latitude confirm the patchy structure of the hot Galactic halo. The 3/4-keV band observations help define the spatial structure of the hotter emission and thus its possible source(s).
- Publication:
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American Astronomical Society Meeting Abstracts
- Pub Date:
- December 1998
- Bibcode:
- 1998AAS...193.8304G