AAS Meeting #193 - Austin, Texas, January 1999
Session 83. Interstellar Medium
Oral, Friday, January 8, 1999, 10:00-11:30am, Room 9(C)

[Previous] | [Session 83] | [Next]

[83.04D] The Three-Dimensional Structure of the Hot Interstellar Medium

C. E. Grant, D. N. Burrows (Penn State University)

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 \mum 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).

The author(s) of this abstract have provided an email address for comments about the abstract: cgrant@astro.psu.edu

[Previous] | [Session 83] | [Next]