Hercules X-1 (Her X-1): New results from the past decade of observations

Abstract

Hercules X-1 is an accreting X-ray binary with well-determined properties based on measurements of light-curves and spectra since its discovery in 1972. Since discovery, it has been observed with most major X-ray astronomy instruments. Analyses of Her X-1 over the past decade include, among others, observations from RXTE/PCA and ASM, Suzaku, NuSTAR, AstroSat and Swift/BAT. These have added to the range of phenomena detected from this system. New aspects of the binary are reviewed. The data are being used to test models for the system, including the nature of the companion star (HZ Her), the accretion column on the neutron star, the shape of the accretion disk and its shadow, and the accretion stream.