Location of Repository

CONSTRAINING SPINS OF SUPERMASSIVE BLACK HOLES FROM TEV VARIABILITY. II. FULLY GENERAL RELATIVISTIC CALCULATIONS

By Yan-rong Li, Ye-fei Yuan, Jian-min Wang, Jian-cheng Wang and Shu Zhang

Abstract

The fast variability of energetic TeV photons from the center of M87 has been detected, offering a new clue to estimate spins of supermassive black holes (SMBHs). We extend the study of Wang et al. (2008) by including all of the general relativistic effects. We numerically solve the full set of relativistic hydrodynamical equations of the radiatively inefficient accretion flows (RIAFs) and then obtain the radiation fields around the black hole. The optical depth of the radiation fields to TeV photons due to pair productions is calculated in the Kerr metric. We find that the optical depth strongly depends on (1) accretion rates as τ TeV ∝ ˙M 2.5−5.0; (2) black hole spins; and (3) location of the TeV source. Jointly considering the optical depth and the spectral energy distribution radiated from the RIAFs, the strong degeneration of the spin with the other free parameters in the RIAF model can be largely relaxed. We apply the present model to M87, wherein the RIAFs are expected to be at work, and find that the minimum specific angular momentum of the hole is a ∼ 0.8. The present methodology is applicable to M87-like sources with future detection of TeV emissions to constrain the spins of SMBHs. Subject headings: black hole physics — galaxies: individual (M87) 1

Year: 2008
OAI identifier: oai:CiteSeerX.psu:10.1.1.315.5156
Provided by: CiteSeerX
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • http://citeseerx.ist.psu.edu/v... (external link)
  • http://arxiv.org/pdf/0904.2335... (external link)
  • Suggested articles


    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.