Abstract Details

Name: Sandeep Rout
Affiliation: Physical Research Laboratory
Conference ID: ASI2021_436
Title : X-ray spectroscopy of MAXI J1631-479: Evidence for non-thermal emission and a massive black hole
Authors and Co-Authors : Sandeep Rout (PRL Ahmedabad), Santosh Vadawale (PRL Ahmedabad)
Abstract Type : Poster
Abstract Category : Stars, ISM and Galaxy
Abstract : MAXI J1631-479 is a galactic black hole binary which went into outburst for the first time in December 2018. In the talk I will present the results of our joint spectral analysis of the source using XRT and NuSTAR. During the soft state of the outburst, an excess beyond 50 keV suggests the presence of non-thermal emission. Using a hybrid plasma model, we confirm emission from non-thermal pairs, the signatures of which are rarely detected below 100 keV. We also fit the joint spectrum with relativistic reflection models and constrain the spin and inclination to high values. We further fit the soft state spectrum with general relativistic disk models to constrain the mass. Considering the optical observations as a limit for the disk emission, we constrain the distance to the source to be greater than 4 kpc and consequently a lower limit on mass of the black hole around 20 Msun. This puts the source among the most massive stellar mass black holes in the galaxy.