NuSTAR monitoring of MAXI J1348-630: evidence of high density disc reflection
Abstract
We present the broad-band spectral analysis of all the six hard, intermediate, and soft state NuSTAR observations of the recently discovered transient black hole X-ray binary MAXI J1348-630 during its first outburst in 2019. We first model the data with a combination of a multicolour disc and a relativistic blurred reflection, and, whenever needed, a distant reflection. We find that this simple model scheme is inadequate in explaining the spectra, resulting in a very high iron abundance. We therefore explore the possibility of reflection from a high-density disc. We use two different sets of models to describe the high-density disc reflection: RELXILL-based reflection models, and REFLIONX-based ones. The REFLIONX-based high-density disc reflection models bring down the iron abundance to around the solar value, while the density is found to be $10^{20.3-21.4}\, \rm cm^{-3}$. We also find evidence of a high-velocity outflow in the form of ~7.3 keV absorption lines. The consistency between the best-fitting parameters for different epochs and the statistical significance of the corresponding model indicates the existence of high-density disc reflection in MAXI J1348-630.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- November 2021
- DOI:
- 10.1093/mnras/stab2530
- arXiv:
- arXiv:2109.05380
- Bibcode:
- 2021MNRAS.508..475C
- Keywords:
-
- accretion;
- accretion discs;
- methods: data analysis;
- X-rays: binaries;
- X-rays: individual: MAXI J1348-630;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 15 pages, 12 figures, 5 tables