Semi-analytic general relativistic magnetohydrodynamic solutions for black hole magnetospheres of AGN jets
Abstract
The Event Horizon Telescope (EHT) revealed the ring-like emission structure just around the black hole of M87. Global general relativistic magnetohydrodynamic (GRMHD) simulations have shown that the photons emitted from the accretion disk can make this characteristic structure. While the emission from the jet is expected to be observed in the future EHT observations, global GRMHD simulations have numerical difficulty in treating a very-low-density jet launching area. Our study aims to constrain the density distribution in a jet launching region by reproducing characteristic emission structures of jets. In this work, we have constructed a new way to obtain approximate solutions of black hole magnetospheres. We semi-analytically calculate the force-balance between the fixed field lines that are consistent with GRMHD simulations and analytically derive the distributions of fluid velocity and density along the field lines. Combined with radiative transfer calculations and future observations of jet emission around a black hole, our approximate solutions will be useful to constrain the black hole spin parameter.
- Publication:
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43rd COSPAR Scientific Assembly. Held 28 January - 4 February
- Pub Date:
- January 2021
- Bibcode:
- 2021cosp...43E1404O