Slowly Rotating Accretion Flows around Supermassive Black Holes in Elliptical Galaxies

Event type
Event date
Venue
On-site: Sala Sousa Pinto
Speaker
Razieh Ranjbar (Ferdowsi University)

It has been believed that supermassive black holes (SMBHs) in the majority of nearby galaxies in the universe are powered by accretion flows. Observational evidence and many numerical simulations show of elliptical galaxies have revealed a surprising fact, in the densest regions of massive elliptical galaxies the hot gas rotates very slowly. One of the primary aims of this study is to investigate the global solutions of slowly rotating accretion flows around supermassive black holes in elliptical galaxy centers. We have investigated transonic, steady, non-self-gravitating, viscous accretion flows with a finite and small angular momentum that is an intermediate case between Bondi and advection-dominated accretion flows (ADAFs). Such flows are nearly spherical. In recent years, Bondi solutions and slowly rotating accretion flows, have been developed by taking the gravitational potential of galaxy stars into account. Since our solution is in the region of around 10 parsecs, the gravitational force of a nuclear star is comparable to that of the central black hole and so we study the effect of the potential of galaxy stars on slowly rotating accretion flows. Also, recent observations and simulations suggest that outflows/winds play a significant role in accretion systems and the next step of our solution, we have investigated the structure of the accretion flow in presence of an outflow. In this study, we have considered an unknown mechanism for removing mass, angular momentum, and energy by outflows.