Estimating the Spin of MAXI J1820+070 From Soft State by Insight‐HXMT

ABSTRACT MAXI J1820+070, discovered by the Monitor of All‐sky X‐ray Image (MAXI) in 2018, is a well‐known black hole X‐ray binary. This study presents a detailed spectral analysis using 2018 observations from the Insight Hard X‐ray Modulation Telescope (HXMT). We explored the evolution of the Fe line shape and found it stable at 6.4 keV in the high/soft state, indicating the inner radius of the accretion disk remains at the Innermost Stable Circular Orbit. Additionally, we estimated the black hole spin () using the continuum fitting method, obtaining a spin of , consistent with previous results. Through these findings, this study has contributed to the spectral analysis and spin parameter estimation of black hole X‐ray binary systems, offering valuable insights into black hole behavior and its role in cosmology.