Penn State is one of the centers for analysis of these data.
Several examples are available for display.
In optical light these are produced by light from a bright nebula being absorbed in an intervening dark cloud. In fact, the X-ray sky somewhat resembles the night sky as seen from the downtown of a large city, where light from street lamps scattered in the atmosphere produces a bright haze that obscures all but the brightest stars. These measurements have permitted the first unambiguous observational proof of the existence of million degree gas in the galactic halo, and are providing important clues to the distribution of hot gas in the galactic disk as well. Studies of soft X-ray shadows are being pursued by Evan Pugh Professor Gordon Garmire and by Dr. David Burrows . Several graduate students are also involved in this work.