A GHz Flare in a Quiescent Black Hole and A Determination of the Mass Accretion Rate
نویسندگان
چکیده
If the total energy of a radio flare is known, one can estimate the mass accretion rate of the disk by assuming equipartition of magnetic energy and the gravitational potential energy of accreting matter. We present here an example of how such an estimate could be done. Our recent radio observation using the Giant Meter Radio Telescope (GMRT) of the galactic black hole transient A0620-00 at 1.280 GHz revealed a micro-flare of a few milli-Jansky. Assuming a black hole mass of 10M⊙ for the compact object, we find the accretion rate to be at the most Ṁ = (8.5±1.4)×10−11( 3 )M⊙ yr, where, x is the distance from the hole in units of Schwarzschild radius. This is consistent with the earlier estimate of the accretion rate based on optical and X-ray observations. We claim that this procedure is general enough to be used for any black hole candidate.
منابع مشابه
The Giant X-Ray Flare of NGC 5905: Tidal Disruption of a Star, a Brown Dwarf, or a Planet?
We model the 1990 giant X-ray flare of the quiescent galaxy NGC 5905 as the tidal disruption of a star by a supermassive black hole. From the observed rapid decline of the luminosity, over a timescale of a few years, we argue that the flare was powered by the fallback of debris rather than subsequent accretion via a thin disk. The fallback model allows constraints to be set on the black hole ma...
متن کاملA Simplified Solution for Advection Dominated Accretion Flows with Outflow
The existence of outflow in the advection dominated accretion flows has been confirmed by both numerical simulations and observations. The outow models for ADAF have been investigated by several groups with a simple self similar solution. But this solution is inaccurate at the inner regions and can not explain the emitted spectrum of the flow; so, it is necessary to obtain a global solution for...
متن کاملElectron Acceleration around the Supermassive Black Hole at the Galactic Center
The recent detection of variable infrared emission from Sagittarius A*, combined with its previously observed flare activity in X-rays, provides compelling evidence that at least a portion of this object’s emission is produced by nonthermal electrons. We show here that acceleration of electrons by plasma wave turbulence in hot gases near the black hole’s event horizon can account both for Sagit...
متن کاملLithium Production on a Low-mass Secondary in a Black Hole Soft X-ray Transient
We examine production of Li on the surface of a low-mass secondary in a black hole soft X-ray transient (BHSXT) through the spallation of CNO nuclei by neutrons which are ejected from a hot (> 10 MeV) advectiondominated accretion flow (ADAF) around the black hole. Using updated binary parameters, cross sections of neutron-induced spallation reactions, and mass accretion rates in ADAF derived fr...
متن کاملAccretion Rates onto Massive Black Holes in Four Quiescent Elliptical Galaxies.
Four quiescent elliptical galaxies were imaged with the NRAO VLA at 8.5 GHz. Within the context of canonical advection-dominated accretion flows (ADAFs), these VLA images plus published black hole masses constrain the accretion rates to be less than 1.6x10-4, less than 3.6x10-4, </=7.8x10-4, and </=7.4x10-4 of the Eddington rates. These ADAF accretion rates derived at 8.5 GHz have important imp...
متن کامل