Thermal solutions of strongly magnetized disks and the hysteresis in X-ray binaries

• DOI: 10.48550/arxiv.2410.12920
• Publication Date: 2024-10-16
• Authors: Nicolas Scepi; Jason Dexter; Mitchell C. Begelman; G. Marcel; Jonathan Ferreira; Pierre-Olivier Pe...
• Keywords: Atmospheric temperature range; Hysteresis

X-ray binaries (XRBs) exhibit spectral hysteresis for luminosities in the range $10^{-2}\lesssim L/L_\mathrm{Edd}\lesssim 0.3$, with a hard state that persists from quiescent up to $\gtrsim 0.3L_\mathrm{Edd}$, transitioning soft survives decreasing down $\sim 10^{-2}L_\mathrm{Edd}$. We present possible approach explain this behavior based on thermal properties of magnetically arrested disk simulation. By post-processing simulation include radiative effects, we solve all equilibrium solutions as accretion rate, $\dot{M}$, varies along XRB outburst. For an assumed scaling scale height and speed temperature, find there exists two $ 10^{-3}\lesssim\dot{M}/\dot{M}_{\rm Eddington} \lesssim 0.1$ at $r=8\:r_g$ ($ 4\times10^{-2}\lesssim\dot{M}/\dot{M}_{\rm 0.5$ $r=3\:r_g$) : cold, optically thick one hot, thin one. This opens possibility natural right XRBs. stress our scenario does not require invoke strong-ADAF principle nor it magnetization change In fact, requires highly magnetized reproduce soft-to-hard transition luminosities. Hence, prediction is should be jet, although possibly very weakly dissipative, also predict if active galactic nuclei (AGN) have similar cycles are strongly magnetized, they undergo much lower $L/L_\mathrm{Edd}$ than