New estimates of the spin and accretion rate of the black hole M87*

Abstract

In this paper we use the imaging results of M87* from the EHT to calculate the rotational velocity of the inner edge of the accretion disk and find a value of $\sim$0.14c. We then calculate the dimensionless spin parameter, $a$, of the black hole, obtaining a value of $a\sim 0.8$. We deduce that this is probably a lower limit. We go on to use the results of the EHT polarization study of the magnetic field direction in the accretion disk of M87* as a proxy for the direction of motion of the spiralling accreting matter in this highly ionized disk. This direction is defined by the vector sum of the tangential rotation velocity and the inward radial accretion velocity. We thus calculate the accretion velocity to be $\sim$ (7 $\pm$ 0.7) $\times$ $10^7$~ms${}^{-1}$. We go on to estimate a range of values for the accretion rate from the inner disk to be $\sim$4 $\times$ 10${}^{-5}$ to $\sim$4 $\times$ 10${}^{-1}$ M${}_{\odot }$yr${}^{-1}$, and a range of values for the accretion power to be $\sim$10${}^{34}$ to 10${}^{38}$ J/s. This is the same range as the power of the jet, making it consistent with accretion-driven jet models.

6 pages, 3 figures

References in corpus (8)

• First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
• First M87 Event Horizon Telescope Results. VI. The Shadow and Mass of the Central Black Hole
• First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole
• First M87 Event Horizon Telescope Results. V. Physical Origin of the Asymmetric Ring
• First M87 Event Horizon Telescope Results. VIII. Magnetic Field Structure near The Event Horizon
• First M87 Event Horizon Telescope Results. VII. Polarization of the Ring
• Jet Launching Structure Resolved Near the Supermassive Black Hole in M87
• Brightness Asymmetry of Black Hole Images as a Probe of Observer Inclination

Cited by in corpus (5)

• Regular Black Holes from Proper-Time flow in Quantum Gravity and their Quasinormal modes, Shadow and Hawking radiation
• Radiative properties of thin accretion disks around rotating short-hairy black holes
• Limiting the Yukawa Gravity through the Black Hole Shadows of Sgr A* and M87*
• Deciphering signatures of Kerr-Sen black holes in presence of plasma from the Event Horizon Telescope data
• Investigating the interplay of the braneworld gravity and the plasma environment on the black hole shadow