Mass and Angular Momentum of Black Holes: An Overlooked Effect of General Relativity Applied to the Galactic Center Black Hole Sgr A*

Abstract

I report the discovery of a new effect of General Relativity which is important to understand very rapidly rotating (Kerr) black holes. The orbital velocity of a test particle is no longer a monotonic function of the orbit radius when the spin of the black hole is >0.9953, but displays a local minimum-maximum structure for radii smaller than 1.8 gravitational radii. There the rate of change of the orbital velocity per radius unit equals the radial epicyclic frequency and is exactly one third of the polar epicyclic frequency, suggesting a 3:1 resonant oscillatory motion of the particle. If associated with the observed quasi-periods - including the most recent 2005/2006 data - the mass of the supermassive black hole Sgr A* in the centre of the our Galaxy is determined to 3.3 million solar masses and the spin is 0.99616.

arXiv comment11 pages, 5 figures, updated version of a talk given at the 2005 Frascati Workshop, Vulcano, Italy, May 23 - 28

References in corpus (7)

• Stellar Orbits Around the Galactic Center Black Hole
• Near-infrared flares from accreting gas around the supermassive black hole at the Galactic Centre
• SINFONI in the Galactic Center: young stars and IR flares in the central light month
• X-ray flares reveal mass and angular momentum of the Galactic Center black hole
• Measuring mass and angular momentum of black holes with high-frequency quasi-periodic oscillations
• Stochastic Electron Acceleration During the NIR and X-ray Flares in Sagittarius A*
• The Aschenbach effect: unexpected topology changes in motion of particles and fluids orbiting rapidly rotating Kerr black holes

Cited by in corpus (8)

• Multi-resonance orbital model of high-frequency quasi-periodic oscillations: possible high-precision determination of black hole and neutron star spin
• Kerr black hole parameters in terms of red/blue shifts of photons emitted by geodesic particles
• LNRF-velocity hump-induced oscillations of a Keplerian disc orbiting near-extreme Kerr black hole: A possible explanation of high-frequency QPOs in GRS 1915+105
• Aschenbach effect for spinning particles in Kerr spacetime
• Correlation between 3:2 QPO pairs and Jets in Black Hole X-ray Binaries
• Black Holes Admitting Strong Resonant Phenomena
• General relativistic formulas for mass and spin of a Kerr black hole in terms of redshifts and orbital parameters
• Extended orbital resonance model with hump-induced oscillations