New X-ray observations of Hercules X-1 with AstroSat
Abstract
The X-ray binary system Hercules X-1 has been observed by X-ray instruments on the AstroSat multiwavelength satellite. The 35-day phases of the observations were determined using Swift BAT monitoring. One AstroSat observation was taken during Low State and early Turn-On to Main High State. A second observations was taken during the peak of Main High State. X-ray lightcurves and spectra from the different system states are compared. The Main High spectrum shows a power-law continuum, a soft (0.1 keV) black-body component , a 1 keV emission broad line feature and a 6.5 keV iron emission line. The parameters of these components are consistent with previous Main High broad-band X-ray spectral observations. In Main High State, evidence is found, in the spectrum, for a new feature: a highly-ionized absorber. This is consistent with the recently-detected corona in Her X-1. Comparing different X-ray states of Hercules X-1, the strengths of the spectral components varies greatly. This is consistent with previous multi-state studies, such as carried out by RXTE. The physical origin of the spectrum variations is discussed in terms of the precessing accretion disk in the binary system.
- Publication:
-
American Astronomical Society Meeting Abstracts #233
- Pub Date:
- January 2019
- Bibcode:
- 2019AAS...23346802L