On Aug. 5, 1992 BATSE discovered the bright X‐ray transient GRO J0422+32, also known as Nova Per 1992. The COMPTEL instrument (0.75–30 MeV) aboard CGRO observed this black‐hole candidate twice. During the first observation, which started when the X‐ray flux was at its maximum, GRO J0422+32 was detected up to 2 MeV. The fluxes in the 0.75–1 and 1–2 MeV range were signficantly higher than expected based on an extrapolation of the contemporaneous OSSE data. The COMPTEL spectral points can be interpreted as evidence for a Wien‐type spectral component with temperature k T≊300 keV. During the second observation, 3 weeks after the first, GRO J0422+32 was detected only up to 1 MeV.
Space Science Center, Physics
AIP Conference Proceedings
Digital Object Identifier (DOI)
MeV emission from the black‐hole candidate GRO J0422+32 measured with COMPTEL van Dijk, R. and Bloemen, H. and Hermsen, W. and Collmar, W. and Diehl, R. and Greiner, J. and Lichti, G. G. and Schönfelder, V. and Strong, A. and Bennett, K. and Hanlon, L. and Winkler, C. and McConnell, M. and Ryan, J., AIP Conference Proceedings, 304, 197-201 (1994), DOI:http://dx.doi.org/10.1063/1.45619
© 1994 American Institute of Physics