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

TL;DR

This paper measures the spin of the black hole in MAXI J1348-430 using Insight-HXMT X-ray data, revealing a high spin value through spectral reflection analysis.

Contribution

The study applies the relxill reflection model to multiple spectra to accurately determine the black hole's spin, demonstrating a novel approach with high-confidence constraints.

Findings

Black hole spin parameter is approximately 0.82.

Reflection signatures are clearly detected in the spectra.

The method provides a robust spin measurement with 90% confidence.

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, with the Gas Slit Camera (GSC) 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 disk plus power law models, X-ray reflection signatures were clearly visible in some of these observations. We use the state-of the-art 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% confidence level (statistical only).