Previous abstract Next abstract
The underlying mechanism responsible for variations in the observed 1/4 keV X-ray background is not well understood. Measurements of soft X-ray shadows cast by clumps of neutral material provide a direct method of determining the spatial distribution of the hot gas responsible for the soft X-ray background. The observed contrast of an X-ray shadow depends on the density and size of the cool absorbing cloud, and on the amount of foreground and background soft X-ray emitting gas. We present here a dramatic example of this shadowing effect as observed by the ROSAT X-ray telescope and position sensitive proportional counter (PSPC). The shadow discussed here is particularly dark with high contrast indicating that the vast majority of the X-ray emitting gas in this direction extends beyond the cloud. This work was supported by the NASA ROSAT Guest Observer Program under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. W-7405-ENG-48.
Saturday program listing