- Super-soft x-ray source
A super soft X-ray source is an astronomical source of very low energy
X-rays . Soft X-rays have energies in the 0.09 to 2.5keV range, whereas hard X-rays are in the 1-20 keV range [ [http://library.thinkquest.org/27930/supersoft.htm Supersoft X-Ray Sources] ] . Super soft X-rays are believed to be produced by steadynuclear fusion on awhite dwarf 's surface of material pulled from a binary companion [ [http://www.mpe.mpg.de/~jcg/sss/sss_high.html Super Soft X-ray Sources - Discovered with ROSAT] (Max Planck Institute for Extraterrestrial Physics )] . This requires a flow of material sufficiently high to sustain the fusion. Contrast this with thenova , where less flow causes the material to only fuse sporadically. Super soft X-ray sources can evolve intotype Ia supernova , where a sudden fusion of material destroys the white dwarf, and neutron stars, through collapse [ [http://www.mpe.mpg.de/~jcg/sss/sssw.html Proceedings of the Workshop on Supersoft X-ray Sources] held at theMax Planck Institute for Extraterrestrial Physics ] .History
Super soft X-ray sources were first discovered by the
Einstein Observatory . Further discoveries were made byROSAT [ [http://www.aip.de/~jcg/sss/ssscat.html Catalog of Supersoft X-ray Sources] ] .References
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