Five years in the life of Cygnus X-1: BATSE long-term monitoring
- 1 January 1997
- conference paper
- Published by AIP Publishing
- Vol. 410 (1) , 834-838
- https://doi.org/10.1063/1.53985
Abstract
The hard X-ray emission from Cygnus X-1 has been monitored continually by BATSE since the launch of CGRO in April 1991. We present the hard X-ray intensity and spectral history of the source covering a period of more than five years. Power spectral analysis shows a significant peak at the binary orbital period. The 20–100 keV orbital light curve is roughly sinusoidal with a minimum near superior conjunction of the X-ray source and an rms modulation fraction of approximately 1.7%. No longer-term periodicities are evident in the power spectrum. We compare our results with other observations and discuss the implications for models of the source geometry.Keywords
All Related Versions
This publication has 0 references indexed in Scilit: