NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
ROSAT detection of an X-ray shadow in the 1/4-keV diffuse background in the Draco nebulaThe detection by the Roentgen satellite (ROSAT) X-ray telescope of a shadow in the 1/4-keV (C-band, 0.1 to 0.284 keV) cosmic diffuse background is reported. The location and morphology of the local minimum in X-rays are in clear agreement with a discrete H I cloud. The shadow is very deep with a minimum level at 50 percent of the surrounding emission; therefore, a minimum of 50 percent of the observed off-cloud flux must originate on the far side of the cloud. The analysis of H I velocity components links the cloud with the Draco nebula (distance of about 600 parsecs); it then follows that there is significant 1/4-keV X-ray emission at large distance (more than 400 parsecs) from the galactic plane along this line of sight. The extent of the distant emission region is uncertain, and if it indicates the existence of a hot galactic corona, it must be patchy in nature.
Document ID
19910057512
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Snowden, S. L.
(Max-Planck-Institut fuer extraterresrische Physik, Garching, Federal Republic of Germany; Wisconsin, University Madison, United States)
Mebold, U.
(Max-Planck-Inst. fuer Extraterrestrische Physik Garching, Germany)
Hirth, W.
(Max-Planck-Inst. fuer Extraterrestrische Physik Garching, Germany)
Herbstmeier, U.
(Bonn, Universitaet Federal Republic of Germany, United States)
Schmitt, J. H. M.
(Max-Planck-Institut fuer extraterrestrische Physik Garching, Federal Republic of Germany, United States)
Date Acquired
August 15, 2013
Publication Date
June 14, 1991
Publication Information
Publication: Science
Volume: 252
ISSN: 0036-8075
Subject Category
Space Radiation
Accession Number
91A42135
Funding Number(s)
CONTRACT_GRANT: NAG5-1438
CONTRACT_GRANT: DFG-ME-745/7-2
CONTRACT_GRANT: NAG5-629
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available