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

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 ($a_{*}$) using the continuum fitting method, obtaining a spin of $a_{*}{=0.122}_{-0.016}^{+0.013}$, 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.