The Soft State of Cygnus X-1 Observed with NuSTAR: A Variable Corona and a Stable Inner Disk

D. J. Walton, J. A. Tomsick, K. K. Madsen +17

We present a multi-epoch hard X-ray analysis of Cygnus X-1 in its soft state based on four observations with NuSTAR. Despite the basic similarity of the observed spectra, there is…