Related papers: Luminous hot accretion disks
Neutrino-cooled accretion disks can form in the aftermath of neutron-star mergers as well as during the collapse of rapidly rotating massive stars (collapsars) and the accretion-induced collapse of rapidly rotating white dwarfs. Due to…
When the accretion rate is more than a small fraction of Eddington, the inner regions of accretion disks around black holes are expected to be radiation-dominated. However, in the alpha-model, these regions are also expected to be thermally…
We investigate the model of the disc/corona accretion flow around the black hole. The model, parameterized by the total (i.e. disk plus corona) accretion rate, $\dot m$, mass of the black hole, $M$ and the viscosity parameter, $\alpha$,…
We present the first results from two-dimensional simulations of radiatively-efficient accretion of metal-free gas onto intermediate-mass black holes. We fix the shape of the spectral energy distribution of the radiation produced near the…
To what extent can the one-dimensional slim disk model reproduce the multi-dimensional results of global radiation-hydrodynamic simulations of super-Eddington accretion? With this question in mind, we perform systematic simulation study of…
We report results from simulations in general relativity of magnetized disks accreting onto merging black hole binaries, starting from relaxed disk initial data. The simulations feature an effective, rapid radiative cooling scheme as a…
By performing a viscous hydrodynamics simulation in general relativity for super-Eddington accretion flows onto massive black holes of mass $M=10^5$--$10^7M_\odot$, we discuss a formation scenario for black hole-envelope systems. We…
Disk accretion onto black holes is accompanied by collimated outflows (jets). In active galactic nuclei (AGN), the kinetic energy flux of the jet may exceed the bolometric luminosity of the disk a few orders of magnitude. This phenomena can…
We propose a geometrically thick, super-Eddington accretion disk model, where an optically thick wind is not necessary, to understand ultraluminous supersoft sources (ULSs). For high mass accretion rates $\dot M \ga 30\dot M_{\rm Edd}$ and…
The supercritical disk accretion flow with radiatively driven outflows is studied based on two-dimensional radiation-hydrodynamic simulations for a wide range of the mass input rate, $\dot{M}_{\rm input}$, which is the mass supplied from…
The rapid assembly of the massive black holes that power the luminous quasars observed at $z \sim 6-7$ remains a puzzle. Various direct collapse models have been proposed to head-start black hole growth from initial seeds with masses $\sim…
Accretion in the nuclei of active galaxies may occur chaotically. This can produce accretion discs which are counter-rotating or strongly misaligned with respect to the spin of the central supermassive black hole (SMBH), or the axis of a…
Observations of the hot gas surrounding Sgr A* and a few other nearby galactic nuclei imply electron and proton mean free paths comparable to the gas capture radius: hot accretion likely proceeds under weakly-collisional conditions in these…
The standard equilibrium for radiation-dominated accretion disks has long been known to be viscously, thermally, and convectively unstable, but the nonlinear development of these instabilities---hence the actual state of such disks---has…
We perform two-dimensional hydrodynamic simulations to study the non-rotating gas flow in the region from 1-1000 parsec. This region connects the galaxy scale and the accretion disk scale. The gas is irradiated by the photons generated by…
We study the properties of two-temperature accretion flow around a non-rotating black hole in presence of various dissipative processes where pseudo-Newtonian potential is adopted to mimic the effect of general relativity. The flow…
The X-ray spectral and timing properties of ultraluminous X-ray sources (ULXs) have many similarities with the very high state of stellar-mass black holes (power-law dominated, at accretion rates greater than the Eddington rate). On the…
Geometrically thick disks may form after tidal disruption events, and rapid accretion may lead to short flares followed by long-term, lower-level emission. Using a novel accretion disk code which relies primarily on global conservation laws…
Observations show that the accretion flows in low-luminosity active galactic nuclei (LLAGNs) probably have a two-component structure with an inner ADAF and an outer truncated accretion disk. As shown by Taam et al. (2012), the truncation…
Regular black holes are crucially important as approaches to solving the singularity problem, and in this paper, the accretion disk of Bardeen and Hayward models have been studied. For this purpose, we calculated the physical properties of…