Determining the Three-Dimensional Structure of the Hot Interstellar Medium

Session 51 - Interstellar Medium II.
Display session, Thursday, January 08
Exhibit Hall,

[51.10] Determining the Three-Dimensional Structure of the Hot Interstellar Medium

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

The diffuse soft X-ray background below 1 keV is dominated by a superposition of hot Galactic plasma emission, both local and from the Galactic halo. A method for differentiating the local from the more distant emission is through the use of X-ray shadows in which cold molecular clouds absorb the distant X-rays. We will present results of analysis of ROSAT PSPC data towards ten molecular clouds covering a range of Galactic latitudes and distances. Spatial anti-correlation between IRAS 100 \mum and X-ray emission indicates the strength of the absorption effect. For the 1/4-keV band, the low latitude fields will help define the size of the local hot bubble, while the high latitude fields will constrain the extent and importance of million degree halo gas. In the 3/4-keV band, both low and high latitude fields will be used to understand the source(s) of the emission by determining its spatial structure. Comparisons will be made with the complementary surveys by Kuntz, Snowden and Verter, 1997 (ApJ 484, 245), Juda, 1996 (BAAS 188, 07.19), and Wang and Yu, 1995 (AJ 109, 698).

Program listing for Thursday