2025ApJ...984..115C

We present an X-ray spectral analysis of a black hole X-ray binary, SLX 1746-331, during the 2023 outburst using five Insight-HXMT observations. We jointly use the reflection model relxillcp and the general relativistic thermal thin disk model kerrbb to fit the spectra from 2 to 100 keV. By jointly fitting the five spectra, we constrain the black hole mass to be M = 5.8 ± 0.3M_⊙ and the dimensionless spin parameter to be ${a}_{* }=0.8{8}_{-0.02}^{+0.01}$ (90% statistical confidence). The reflection model shows that SLX 1746-331 is a high-inclination system with the inclination angle $i=63\mathop{.}\limits^{{\rm{^\circ }}}{7}_{-1.0}^{+1.3}$, and the accretion disk has a density ${\rm{log}}N\sim 16\,{{\rm{cm}}}^{-3}$. In addition, with the different reflection model relxilllp, which assumes a lamppost geometry corona, we still obtain similar results.