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Session 12 - Degenerate Stars & Supernovae.
Oral session, Monday, June 09
North Main Hall C/D,
The 2-60 keV X-ray spectrum of the Cassiopeia A supernova remnant has been measured using the Rossi X-ray Timing Explorer. This spectrum clearly reveals a nonthermal high-energy X-ray ``tail.'' A timing analysis of this data does not show evidence of pulsations at frequencies between about 10^-3 Hz and 1024 Hz. Of the possible nonthermal continuum emission mechanisms---a pulsar, inverse Compton scattering, nonthermal bremsstrahlung emission, and synchrotron radiation---an analysis of the spectrum suggests that the high-energy X-ray emission is dominated by synchrotron emission between about 10 keV and 60 keV and (2) that a significant fraction of the 2-10 keV emission spectrum is synchrotron radiation. If Cassiopeia A does emit such X-ray synchrotron radiation, these results support the hypothesis that Galactic cosmic rays are accelerated predominantly in supernova remnants.
The author(s) of this abstract have provided an email address for comments about the abstract: glenn.allen@gsfc.nasa.gov