Related papers: Funnel-flow accretion onto highly magnetized neutr…
We present results from our magnetohydrodynamical simulations of accretion flows onto black holes. Our main focus is the interplay between inflows and related outflows. We consider applications of such flows to the Galatic center and low…
The pulsed X-ray emission from the neutron star surface acts as a window to study the state of matter in the neutron star interior. For accreting millisecond pulsars, the surface X-ray emission is generated from the `hotspots' formed due to…
A major uncertainty in the structure and dynamics of magnetized, radiation pressure dominated neutron star accretion columns in X-ray pulsars and pulsating ultraluminous X-ray sources is that they are thought to be subject to the photon…
We present a model for the anomalous X-ray pulsars (AXPs) in which the emission is powered by accretion from a fossil disk, established from matter falling back onto the neutron star following its birth. The time-dependent accretion drives…
Recently, we have proposed a model for the screening of the magnetic field of an accreting neutron star by the accreted material flowing from the polar regions towards the equator and sinking there underneath the surface (Choudhuri &…
In [Gusakov et al.\ PRD, 96, 103012, (2017)], we proposed a self-consistent method to study the quasistationary evolution of the magnetic field in neutron-star cores. Here we apply it to calculate the instantaneous particle velocities and…
To estimate the feasibility of dense-matter phase transition, we studied the evolution of the central density as well as the baryon chemical potential of accreting neutron stars. We compared the thin-disk accretion with and without the…
We study the accretion flow of a hot gas captured by the black hole gravity in the presence of a thin cold accretion disk. Such geometrical arrangement is expected in Active Galactic Nuclei (AGN) and in galactic X-ray binary systems because…
Disk accretion onto a magnetized star occurs in a variety of astrophysical contexts, from young stars to X-ray pulsars. The magnetohydrodynamic interaction between the stellar field and the accreting matter can have a strong effect on the…
This paper reports on the detailed rp-process reaction flow on an accreting neutron star and the resulting ashes of a type I X-ray burst. It is obtained by coupling a 298 isotope reaction network to a self-consistent one-dimensional model…
We report on the second phase of our study of slightly rotating accretion flows onto black holes. We consider magnetohydrodynamical (MHD) accretion flows with a spherically symmetric density distribution at the outer boundary, but with…
The problem of disk accretion onto the surface of a neutron star with a weak magnetic field at a luminosity exceeding several percent of Eddington is reduced to the problem of the braking of a hypersonic flow with a velocity that is 0.4-0.5…
Molecular clouds in the interstellar medium suffer gravitational instabilities that lead to the formation of one or multiple stars. A recently formed star inside a cold cloud communicates its gravitational force to the surrounding…
In this work we would like to address the issue of shock formation in black hole accretion discs. We provide a {\it generalized two parameter solution scheme} for multi-transonic, accretion and wind around Schwarzschild black holes, by…
The properties of axisymmetric accretion flows of cold adiabatic gas with zero total energy in the vicinity of a Newtonian point mass are characterized by a single dimensionless parameter, the thickness of incoming flow. In the limit of…
High luminosity accretion onto a strongly magnetized neutron star results in a radiation pressure dominated, magnetically confined accretion column. We investigate the dynamics of these columns using two-dimensional radiative relativistic…
Young low-mass stars are characterized by ejection of collimated outflows and by circumstellar disks which they interact with through accretion of mass. The accretion builds up the star to its final mass and is also believed to power the…
We present the structure of a low angular momentum accretion flows around rotating compact objects incorporating relativistic corrections up to the leading post-Newtonian order. To begin with, we formulate the governing post-Newtonian…
Transonic accretion flow with self-consistent treatment of random magnetic field is presented.
As another step towards understanding the long-term evolution of the magnetic field in neutron stars, we provide the first simulations of ambipolar diffusion in a spherical star. Restricting ourselves to axial symmetry, we consider a…