Towards the use of the most massive black hole candidates in AGN to test the Kerr paradigm

Abstract

The super-massive objects in galactic nuclei are thought to be the Kerr black holes predicted by General Relativity, although a definite proof of their actual nature is still lacking. The most massive objects in AGN ($M\sim 10^9{M}_{\odot }$) seem to have a high radiative efficiency ($\eta \sim 0.4$) and a moderate mass accretion rate ($L_{\mathrm{bol}}/L_{\mathrm{Edd}}\sim 0.3$). The high radiative efficiency could suggest they are very rapidly-rotating black holes. The moderate luminosity could indicate that their accretion disk is geometrically thin. If so, these objects could be excellent candidates to test the Kerr black hole hypothesis. An accurate measurement of the radiative efficiency of an individual AGN may probe the geometry of the space-time around the black hole candidate with a precision comparable to the one achievable with future space-based gravitational-wave detectors like LISA. A robust evidence of the existence of a black hole candidate with $\eta >0.32$ and accreting from a thin disk may be interpreted as an indication of new physics. For the time being, there are several issues to address before using AGN to test the Kerr paradigm, but the approach seems to be promising and capable of providing interesting results before the advent of gravitational wave astronomy.

12 pages, 6 figures. v2: some typos corrected

References in corpus (15)

• Advection-Dominated Accretion and the Black Hole Event Horizon
• A Metric for Rapidly Spinning Black Holes Suitable for Strong-Field Tests of the No-Hair Theorem
• Apparent shape of super-spinning black holes
• Using LISA EMRI sources to test off-Kerr deviations in the geometry of massive black holes
• Observable Properties of Orbits in Exact Bumpy Spacetimes
• Shape and position of the shadow in the $\delta =2$ Tomimatsu-Sato space-time
• How to observe a non-Kerr spacetime
• Testing the Kerr black hole hypothesis
• Evidence for Rapidly Spinning Black Holes in Quasars
• The final stages of accretion onto non-Kerr compact objects
• GRMHD prediction of coronal variability in accreting black holes
• Constraint on the quadrupole moment of super-massive black hole candidates from the estimate of the mean radiative efficiency of AGN
• Can we constrain the maximum value for the spin parameter of the super-massive objects in galactic nuclei without knowing their actual nature?
• Evolution of the spin parameter of accreting compact objects with non-Kerr quadrupole moment
• Spinning super-massive objects in galactic nuclei up to $a_{\ast }>1$

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