Speaker
Description
Radiative cooling can strongly influence the structure and dynamics of black hole accretion disks. Considering synchrotron and bremsstrahlung emission, we quantify how radiative losses modify the disk structure and the accretion dynamics. We introduce a critical value of the mass accretion rate, ~10^{-5.5} Eddington, above which the cooling by the synchrotron process efficiently radiates the thermal energy of the disk. We show that at higher accretion rates, the disk undergoes a structural transition: cooling substantially reduces the gas thermal pressure, leading to considerably thinner and denser accretion filaments, and a substantial increase in radiative efficiency, relative to lower accretion rates. This lead us to propose a new definition to the disk height. We numerically observe that the jet efficiency vary by a factor of ~2 as the mass accretion rate increases above the critical accretion rate. Our results thus have important observational consequences on the observed signals from both the disk and jets in accreting systems.