COSI Observations of Cyg X-1
Abstract
We report on observations of the accreting black hole Cygnus X-1 performed by the Compton Spectrometer and Imager (COSI): a balloon-borne gamma-ray (0.2-5 MeV) observatory. Using the data from a superpressure balloon flight in 2016, we investigate the variability of the intensity and spectral shape of this source in the soft gamma-ray domain. A hard tail extending to MeV energies in the spectrum has been reported by other experiments such as COMPTEL and INTEGRAL. We will discuss the spectral shape observed by COSI in this context and compare our observations with simultaneous measurements from Swift/BAT (15-50 keV) and MAXI (2-20 keV).
- Publication:
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AAS/High Energy Astrophysics Division
- Pub Date:
- March 2019
- Bibcode:
- 2019HEAD...1711229R