A Combined Model for the X-Ray to Gamma-Ray Emission of Cygnus X-1
Abstract
We use recent data obtained by three (OSSE, BATSE, and COMPTEL) of four instruments on board the Compton Gamma Ray Observatory (CGRO) to construct a model of Cyg X-1 that describes its emission in a broad energy range, from soft X-rays to MeV γ-rays, self-consistently. The γ-ray emission is interpreted to be the result of Comptonization, bremsstrahlung, and positron annihilation in a hot, optically thin, and spatially extended region surrounding the whole accretion disk. For the X-ray emission, a standard corona-disk model is applied. We show that the Cyg X-1 spectrum accumulated by the CGRO instruments during a ~4 year time period between 1991 and 1995, as well as the HEAO 3 γ1 and γ2 spectra, can be well represented by our model. The derived parameters match the observational results obtained from X-ray measurements.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 1998
- DOI:
- 10.1086/305889
- arXiv:
- arXiv:astro-ph/9803170
- Bibcode:
- 1998ApJ...502..428M
- Keywords:
-
- ELEMENTARY PARTICLES;
- GAMMA RAYS: THEORY;
- PLASMAS;
- RADIATION MECHANISMS: NONTHERMAL;
- SCATTERING;
- STARS: INDIVIDUAL CONSTELLATION NAME: CYGNUS X-1;
- Elementary Particles;
- Gamma Rays: Theory;
- Plasmas;
- Radiation Mechanisms: Nonthermal;
- Scattering;
- stars: individual (Cyg X-1);
- Astrophysics
- E-Print:
- 11 pages including 6 ps-figures and 2 tables, latex2e, uses emulateapj.sty (ver. of 18 Sep 96, enclosed), epsfig.sty, times.sty. To appear in July 20, 1998 issue of ApJ (v.502)