Related papers: Neutrino-cooled Accretion Disks around Spinning Bl…
We calculate the structure of accretion disks around Kerr black holes for accretion rates 0.001 - 10 M_sun/s. Such disks are plausible candidates for the central engine of gamma-ray bursts. Our disk model is fully relativistic and treats…
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…
Hyper-accretion discs around black holes emit copious neutrinos and anti-neutrinos. A fraction of the emitted neutrinos convert to electron-positron plasma above the disc through the annihilation reaction $\nu\bar\nu\to e^+e^-$. This…
We study the hydrodynamical evolution of massive accretion disks around black holes, formed when a neutron star is disrupted by a black hole in a binary system. Initial conditions are taken from 3D calculations of coalescing binaries.…
We investigate the structure and stability of hypercritical accretion flows around stellar-mass black holes, taking into account neutrino cooling, lepton conservation, and firstly a realistic equation of state in order to properly treat the…
For accretion rates Mdot~0.1 Msun/s to a few solar mass black hole the inner part of the disk is expected to make a transition from advection dominance to neutrino cooling. This transition is characterized by sharp changes of the disk…
We follow the nuclear reactions that occur in the accretion disks of stellar mass black holes that are accreting at a very high rate, 0.01 to 1 solar masses per second, as is realized in many current models for gamma-ray bursts (GRBs). The…
We present a detailed, two dimensional numerical study of the microphysical conditions and dynamical evolution of accretion disks around black holes when neutrino emission is the main source of cooling. Such structures are likely to form…
We calculate the nuclear composition of matter in accretion disks surrounding stellar mass black holes as are thought to accompany gamma-ray bursts (GRBs). We follow a mass element in the accretion disk starting at the point of nuclear…
We study the neutrino scattering off a rotating black hole with a realistic accretion disk permeated by an intrinsic magnetic field. Neutrino trajectories in curved spacetime as well as the particle spin evolution in dense matter of an…
Many models of Gamma Ray Bursts invoke a central engine consisting of a black hole of a few solar masses accreting matter from a disk at a rate of a fraction to a few solar masses per second. Popham et al. and Narayan et al. have shown…
A fraction of neutrino emission from GRB accretion disks annihilates above the disk, creating e+- plasma that can drive GRB explosions. We calculate the efficiency of this annihilation using the recent detailed model of hyper-accretion…
In this review, I summarize the main X-ray/hard X-ray properties of the accretion flows around black holes and neutron stars based on recent broad-band spectral and timing observations performed by the BeppoSAX and Rossi X-ray Timing…
A stellar-mass black hole, embedded within the accretion disk of an active galactic nuclei (AGN), has the potential to accrete gas at a rate that can reach approximately $\sim 10^9$ times the Eddington limit. This study explores the…
We report on simulations in general relativity of magnetized disks onto black hole binaries. We vary the binary mass ratio from 1:1 to 1:10 and evolve the systems when they orbit near the binary-disk decoupling radius. We compare (surface)…
Accretion disks with masses ~0.001-0.1 Msun form during the merger of neutron star (NS)-NS and black hole-NS binaries. Initially, such hyper-accreting disks cool efficiently by neutrino emission and their composition is driven neutron-rich…
At the extreme densities and temperatures typical of the central engine of GRBs, the accreting torus is cooled mainly by advection and by neutrino emission. The latter process is dominated by electron and positron capture onto nucleons…
Neutrino-cooled accretion flow around a black hole, produced by a compact binary merger, is a promising scenario for jet formation and magnetic-driven winds to explain short duration gamma ray bursts (GRBs) central engine and kilonovae…
The problem of steady-state accretion to nonrotating black holes is examined. Advection is included and generalized formulas for the radiation pressure in both the optically thick and thin cases are used. Special attention is devoted to…
The structure of the inner edge of the accretion disk around a black hole can be altered, if the matter inside the marginally stable orbit is magnetically connected to the disk. In this case, a non-zero torque is exerted on its inner edge,…