Event Horizon Telescope (EHT) images of the supermassive black hole M87* depict an asymmetric ring of emission. General relativistic magnetohydrodynamic (GRMHD) models of M87* and its accretion disk predict that the amplitude and location of the ring’s peak brightness asymmetry should fluctuate due to turbulence in the source plasma. We compare the observed distribution of brightness asymmetry amplitudes to the simulated distribution in GRMHD models, across varying black hole spin a*. We show that, for strongly magnetized (MAD) models, three epochs of EHT data marginally disfavor ∣a*∣ ≲ 0.2. This is consistent with the Blandford–Znajek model for M87’s jet, which predicts that M87* should have nonzero spin. We show quantitatively how future observations could improve spin constraints and discuss how improved spin constraints could distinguish between differing jet-launching mechanisms and black hole growth scenarios.
- Ring Asymmetry and Spin in M87
- Vadim Bernshteyn - University of ArizonaNicholas S Conroy - Urbana UniversityMichi Bauböck - University of Illinois Urbana-ChampaignPaul Tiede - Harvard UniversityAbhishek V Joshi - University of Illinois Urbana-ChampaignBen S Prather - Los Alamos National LaboratoryCharles F Gammie - University of Illinois Urbana-ChampaignThe Event Horizon Telescope Collaboration The Event Horizon Telescope CollaborationKazunori Akiyama - National Astronomical Observatory of JapanEzequiel Albentosa-Ruíz - Universitat de ValènciaJohn Wardle
- The Astrophysical journal, Vol.1000(2), p.231
- IOP Publishing
- 9924595722501921
- Martin A. Fisher School of Physics
- English
- Journal article