CGRO/OSSE Observations of the Cassiopeia A SNR (Preprint)
CLEMSON UNIV SC DEPT OF PHYSICS AND ASTRONOMY
Pagination or Media Count:
We present all OSSE observations to date of Cassiopeia A supernova remnant. The objectives are to detect the 44Ti lines, one of which has been reportedly detected by COMPTEL, and the hard X-ray continuum above 40 keV, as indicated by HEAO-A2 measurements. Our best fit flux in each of three Ti lines is 1.76 - 1.511.48 x 10expo -5 gamma cmexpo -2 sexpo -1 with Chi2nu 1.01, d.o.f. 1780. The implied 44Ti mass is compatible with explosive nucleosynthesis calculations. OSSE detected also a continuum below 200 keV. This continuum can be fitted equally well with a power law, an exponential, or a thermal bremsstrahlung model. The implied temperature of kT approximately equal to 35 keV can be interpreted as the emission from the shocked circumstellar matter CSM by the primary blastwave of the supernova. Alternatively, the continuum can also be interpreted as bremsstrahlung from accelerated electrons that are also producing the observed radio emission.