Related papers: Two-temperature radiative hot accretion flow aroun…
How many fraction of gas available at the outer boundary can finally fall onto the black hole is an important question. It determines the observational appearance of accretion flows, and is also related with the evolution of black hole mass…
We present a compilation of observed recurrence times ($t_{\rm rec}$) and infer the corresponding local mass-accretion rates ($\dot m$) for type I X-ray bursts, milliHertz quasi-periodic oscillating sources and recurrent novae eruptions. We…
We investigate the transition of a radiatively inefficient phase of a viscous two temperature accreting flow to a cooling dominated phase and vice versa around black holes. Based on a global sub-Keplerian accretion disc model in steady…
Passively cooling neutron stars (NSs) should reach undetectably low surface temperatures $T_s<10^4$ K in less than $10^7$ yr. However, HST observations have revealed likely thermal UV emission from the Gyr-old millisecond pulsars…
Neutron stars (NSs) provide a unique laboratory to probe dark matter (DM) through its gravitational imprint on stellar evolution. We use a two-fluid framework with non-annihilating, asymmetric DM, both fermionic and bosonic, that interacts…
We present a brief, observational review about the study of the cooling behaviour of accretion-heated neutron stars and the inferences about the neutron-star crust and core that have been obtained from these studies. Accretion of matter…
We consider hot accretion onto a rapidly spinning neutron star (or any other compact object with a surface). A radiative hot settling flow has been discovered at low accretion rates in the early work by Medvedev & Narayan (2001) and…
Properties of neutron star are investigated by an available relativistic $ab~ initio$ method, i.e., the relativistic Brueckner-Hartree-Fock (RBHF) model, with the latest high-precision relativistic charge-dependent potentials, pvCD-Bonn A,…
We perform two-dimensional simulations to study how the wind strength changes with accretion rate. We take into account bremsstrahlung, synchrotron radiation and the Comptonization. We find that when the accretion rate is low, radiative…
At luminosities below a few percent of Eddington, accreting black holes switch to a hard spectral state which is very different from the soft blackbody-like spectral state that is found at higher luminosities. The hard state is…
The recent 230 GHz observations from the Event Horizon Telescope collaboration have successfully imaged the supermassive black hole shadow of the M87 galaxy. However, the relatively high radiative efficiency observed in the hot accretion…
We present a model of optically thin, two-temperature, accretion flows using an exact Monte Carlo treatment of global Comptonization, with seed photons from synchrotron and bremsstrahlung emission, as well as with a fully general…
Simulations predict that galaxies grow primarily through the accretion of gas that has not gone through an accretion shock near the virial radius and that this cold gas flows towards the central galaxy along dense filaments and streams.…
Numerical simulation of magnetohydrodynamic (MHD) turbulence makes it possible to study accretion dynamics in detail. However, special effort is required to connect inflow dynamics (dependent largely on angular momentum transport) to…
We present global radiation GRMHD simulations of strongly magnetized accretion onto a spinning, stellar mass black hole at sub-Eddington rates. Using a frequency-dependent Monte Carlo procedure for Compton scattering, we self-consistently…
The paper describes the modelling of the structure and spectra of the hot accretion spots on the surface of young stars with taking into account departures from LTE for hydrogen and helium. It has been found that the existence of the ram…
We examine the effect of thermal conduction on the low-angular momentum hot accretion flow (HAF) around non-rotating black holes accreting mass at very low rate. While doing so, we adopt the conductive heat flux in the saturated form, and…
Two-dimensional (axially symmetric) numerical hydrodynamical calculations of accretion flows which cannot cool through emission of radiation are presented. The calculations begin from an equilibrium configuration consisting of a thick torus…
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…
A weakly magnetized neutron star (NS) undergoing disk accretion should release about a half of its power in a compact region known as the accretion boundary layer. Latitudinal spread of the accreted matter and efficient radiative cooling…