Evidence of relativistic disc reflection in black hole binaries GRS 1758-258 and 1E 1740.7-2942
Abstract
We present the analysis of AstroSat and NuSTAR observations of persistent, Galactic black hole X-ray binaries GRS 1758-258 and 1E 1740.7-2942 carried out within the period of 2016-2021. While GRS 1758-258 is observed to be in dim-soft state and hard state during this period, 1E 1740.7-2942 is found only in hard state. The energy spectra of both sources are found to be characterized by Comptonized continuum along with broad iron emission line. We perform relativistic reflection modelling of the broadband AstroSat (0.6-60 keV) and NuSTAR (3-79 keV) spectra during hard state employing models from relxill family. Modelling includes a blurred (relxillCp) and an unblurred (xillverCp) reflection model that accounts for the Comptonization continuum as well as the radiation reprocessed by Comptonizing region. Our findings suggest that both GRS 1758-258 and 1E 1740.7-2942 are highly inclined systems having inclination angle of 63°-68° and 62°-75° respectively. In addition, our results indicate that the accretion disc of both sources are substantially ionized with GRS 1758-258 having super solar iron abundance i.e., A_{fe}=2.75+0.22_{-0.11} times solar abundance. We discuss the implications of our findings by comparing it with the previous studies
- Publication:
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44th COSPAR Scientific Assembly. Held 16-24 July
- Pub Date:
- July 2022
- Bibcode:
- 2022cosp...44.2267B