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Thermal/non-thermal model of Cyg X-1 in the soft state

Marek Gierlinski·Andrzej A. Zdziarski·Paolo S. Coppi·Juri Poutanen·Ken Ebisawa·W. N. Johnson
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Abstract

We analyze X-ray/gamma-ray observations of Cyg X-1 in the soft state. We find the hybrid thermal/non-thermal model fits the data very well. The significant contribution from the non-thermal electrons is required to account for the observed power law extending without a break to at least 800 keV. The presence of electron-positron pairs in the hot source is unlikely. We propose the geometry in which a cold accretion disk, surrounded by a hot corona, extends down to the last stable orbit. At the observed accretion rate the corona ensures the stability of the cold disk.

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Marek Gierlinski, Andrzej A. Zdziarski, Paolo S. Coppi, Juri Poutanen, Ken Ebisawa, W. N. Johnson. 1997-12-18. Thermal/non-thermal model of Cyg X-1 in the soft state. https://doi.org/10.1016/s0920-5632(98)00231-x

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