The COMPTEL experiment on the Compton Gamma-Ray Observatory (CGRO) has observed the Cygnus region on several occasions since launch. These data represent the most sensitive observations to date of Cygnus X-1 in the 0.75–30 MeV range. The spectrum shows significant evidence for emission extending out to several MeV. These data alone suggest a need to modify the thermal Comptonization models or to incorporate some type of non-thermal emission mechanism. Here we report on the results of an analysis of selected COMPTEL data collected during the first three years of the CGRO mission. These data are then compared with contemporaneous data from both BATSE-EBOP and OSSE. Given a lack of consistency between the OSSE and BATSE-EBOP spectra, it is difficult to draw firm conclusions regarding the exact shape of the spectrum near 1 MeV. A few general conclusions can, however, be drawn from these data.
AIP Conference Proceedings
Digital Object Identifier (DOI)
The MeV spectrum of Cygnus X-1 as observed with COMPTEL McConnell, M. and Bennett, K. and Bloemen, H. and Collmar, W. and Hermsen, W. and Kuiper, L. and Much, R. and Ryan, J. and Schönfelder, V. and Steinle, H. and Strong, A. and van Dijk, R., AIP Conference Proceedings, 410, 829-833 (1997), DOI:http://dx.doi.org/10.1063/1.53984
© 1997 American Institute of Physics