Abstract
The COMPTEL experiment on the Compton Gamma‐Ray Observatory (CGRO) has now observed Cyg X‐1 on four separate occasions during phase 1 and phase 2 of its orbital mission (April, 1991 to August, 1993). Here we report on the results of the latest analysis of these data, which provide a spectrum extending to energies greater than 2 MeV. A spectral analysis of these data, in the context of a classical Comptonization model, indicates an electron temperature much higher than previous hard X‐ray measurements would suggest (200 keV vs 60–80 keV). This implies either some limitations in the standard Comptonization model and/or the need to incorporate a reflected component in the hard X‐ray spectrum. Although significant variability near 1 MeV has been observed, there is no evidence for any ‘MeV excess.’
Department
Space Science Center, Physics
Publication Date
1994
Journal Title
AIP Conference Proceedings
Publisher
AIP Publishing
Digital Object Identifier (DOI)
10.1063/1.45624
Document Type
Conference Proceeding
Recommended Citation
Recent results from COMPTEL observations of Cygnus X‐1 McConnell, M. and Forrest, D. and Ryan, J. and Collmar, W. and Schönfelder, V. and Steinle, H. and Strong, A. and van Dijk, R. and Hermsen, W. and Bennett, K. and Much, R., AIP Conference Proceedings, 304, 230-234 (1994), DOI:http://dx.doi.org/10.1063/1.45624
Rights
© 1994 American Institute of Physics