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Public Seminar of RPg Student: Simulating Accretion Disks and Jets Around Prograde and Retrograde Black Holes

Speaker Miss Cheuk Kwan KAN
Affiliation The University of Hong Kong
Date June 11, 2025 (Wednesday)
Time 04:00 p.m.
Venue Room 522, 5/F, Chong Yuet Ming Physics Building, The University of Hong Kong

Abstract

Through the Blandford-Znajek (BZ) process, a spinning black hole (BH) with a magnetized accretion flow launches relativistic jets -collimated outflows of particles moving at speeds close to the speed of light. These jets are highly energetic and can significantly impact the environment, influencing star formation and galaxy evolution. We conducted general relativistic radiative magnetohydrodynamic (GRRMHD) simulations to investigate the behavior of accretion disks and jets in the regime of super-Eddington magnetically-arrested disks (MAD), an area previously underexplored due to computational limitations. Our simulations reveal a breakdown of the symmetry in jet powers between prograde and retrograde BHs, contrary to predictions from the classical BZ formula, likely linked to the angular frequency of magnetic field lines around the BHs. Additionally, we derived an empirical formula that relates jet power to BH spin and accretion rate, and explored the relations among jet power, magnetic flux, and accretion rate. 

 

Anyone interested is welcome to attend.