PSPC image of the Ophiuchus Dark Clouds
Mosaic of ROSAT PSPC images of the Ophiuchus Dark Clouds in the 3/4 keV band showing the structure of deep shadows (purple indicates low intensity which is the location of the clouds, red indicates high intensity). The data are background subtracted, exposure corrected, and normalized between overlapping pointings, and have been smoothed for presentation. This field is spectacular in the detailed structure of the diffuse X-ray background and tight negative correlation between the cloud material and the surface brightness of the X-rays. The Ophiuchus dark clouds lie nearby in the Galaxy at a distance of ~450 light years. The origin of the strong backlighting of these clouds is still a matter of discussion with the most likely candidates being either emission from Loop I (a nearby supernova remnant or stellar wind bubble which may actually surround the dark clouds) or emission from the Galactic bulge.
HEASARC Guest Observer Facility
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