Constraining the magnetic field in the X-ray corona of Cyg X-1 with INTEGRAL

Abstract

We present six years of INTEGRAL (IBIS, SPI and JEM-X) observations of the BH binary Cygnus X-1. We produced 12 high-quality broad-band spectra (3 keV-1 MeV), representative of the whole range of spectral shapes observed in this source. We have studied the evolution of the physical parameters of the accretion flow across spectral transitions, by using two hybrid thermal/non-* Based on observations with INTEGRAL, an ESA project with instruments and science data centre funded by ESA member states (especially the PI countries: Denmark,