The spin measurement of MAXI J1348-630 using the Insight-HXMT data

Abstract

ABSTRACT We report the results of fitting Insight-HXMT data to the black hole X-ray binary MAXI J1348-430, which was discovered on January 26th, 2019, We also inferred the ionization state and iron abundancewith the Gas Slit Camera on-board MAXI. Several observations at the beginning of the first burst were selected, with a total of 10 spectra. From the residuals of fits using disc plus power-law models, X-ray reflection signatures were clearly visible in some of these observations. We use the state-of-the-art $\tt {relxill}$ series reflection model to fit six spectra with distinct reflection signatures and a joint fit to these spectra. In particular, we focus on the results for the black hole spin values. Assuming Rin = RISCO, the spin parameter is constrained to be $0.82^{+0.04}_{-0.03}$ with 90 per cent confidence level (statistical only).