相关论文: Disks with Jet, ADAF, or EDAF for Sgr A*
Despite significant strides made towards understanding accretion, outflow, and emission processes in the Galactic Center supermassive black hole Sagittarius A*, the presence of jets has neither been rejected nor proven. We investigate here…
Recent work on advection-dominated accretion flows (ADAFs) is reviewed. The article concentrates on an optically thin branch of ADAFs which is present at mass accretion rates below a critical value $\sim(10^{-2}-10^{-1})$ the Eddington…
Sgr A* is an ideal target to study low-luminosity accreting systems. It has been recently proposed that properties of the accretion flow around Sgr A* can be probed through its interactions with the stellar wind of nearby massive stars…
The UV continuum spectrum of quasars and AGN is assumed to originate from an accreting disk surrounding a massive rotating black hole. We discuss the structure and emission spectra of a disk which drives a powerful jet. Due to the large…
In a series of our previous works, a model of radiatively inefficient accretion flows (RIAFs) in a global magnetic field (so called resistive RIAF model) has proved its ability to account for many physical processes taking place in such…
We summarize results from a survey of radiation-dominated black hole accretion flows across a wide range of mass accretion rates, as well as two values of black hole spin and initial magnetic field geometry. These models apply an algorithm…
We present a comprehensive analysis of four near-Eddington black hole accretion models computed by solving the GRMHD equations with full radiation transport. This study focuses on the dynamical effects of magnetic field topology and black…
We discuss the problem of the formation of a large-scale magnetic field in the accretion disks around black holes, taking into account the non-uniform vertical structure of the disk. The high electrical conductivity of the outer layers of…
There is a significant nonlinear correlation between the Eddington ratio (L_bol=L_Edd) and the Eddington-scaled kinetic power (L_kin=L_Edd) of jets in low luminosity active galactic nuclei (AGNs) (Merloni & Heinz). It is believed that these…
The accretion process in a typical S-type symbiotic star, targeting~AG Draconis, is investigated through 3D hydrodynamical simulations using the FLASH code. Regardless of the wind velocity of the giant star, an accretion disk surrounding…
The recent detection of polarized radiation from Sgr A* requires a non-thermal electron distribution for the emitting plasma. The Faraday rotation measure must be small, placing strong limits on the density and magnetic field strength. We…
It seems to be a widely accepted opinion that the types of accretion disks (or flows) generally realized in the nuclei of radio galaxies and in further lower mass-accretion rate nuclei are inner, hot, optically thin, radiatively inefficient…
We present the results of nine simulations of radiatively-inefficient magnetically arrested disks (MADs) across different values of the black hole spin parameter $a_*$: $-0.9$, $-0.7$, $-0.5$, $-0.3$, 0, 0.3, 0.5, 0.7, and 0.9. Each…
Stellar-mass black holes with relativistic jets, also known as microquasars, mimic the behavior of quasars and active galactic nuclei. Because timescales around stellar-mass black holes are orders of magnitude smaller than those around more…
Sagittarius A* (Sgr A*) is a compact radio source at the Galactic center. Observations have confirmed that its mass is approximately (4.1)*10$^{6}$ M$_{\odot}$, and Sgr A* is generally believed to be powered by gas accretion onto a…
Accretion onto black holes often leads to the launch of outflows that significantly influence their surrounding environments. The two primary forms of these outflows are X-ray disk winds-hot, ionized gases ejected from the accretion…
In this Letter we investigate the properties of advection-dominated accretion flows (ADAFs) fed by the evaporation of a Shakura-Sunyaev accretion disk (SSD). In our picture the ADAF fills the central cavity evacuated by the SSD and extends…
Astronomers have discovered many potential black holes in X-ray binaries and galactic nuclei. These black holes are usually identified by the fact that they are too massive to be neutron stars. Until recently, however, there was no…
Astronomers have discovered many potential black holes in X-ray binaries and galactic nuclei. These black holes are usually identified by the fact that they are too massive to be neutron stars. Until recently, however, there was no…
We discuss the problem of the formation of a large-scale magnetic field in the accretion disks around black holes, taking into account the nonuniform vertical structure of the disk. The high electrical conductivity of the outer layers of…