Related papers: MHD simulations of resistive viscous accretion dis…
Magnetohydrodynamic (MHD) simulations have been used to study disk accretion to a rotating magnetized star with an aligned dipole moment. Quiescent initial conditions were developed in order to avoid the fast initial evolution seen in…
The evolution of an initially stellar dipole type magnetosphere interacting with an accretion disk is investigated using numerical ideal MHD simulations. The simulations follow several 1000 Keplerian periods of the inner disk. The initial…
We carried out two dimensional high-resolution magnetohydrodynamic (MHD) simulations of an accretion disk around a weakly magnetized neutron star. General relativistic effects are taken into account by using pseudo-Newtonian potential of…
We present a 3-D ideal MHD simulation of magnetospheric accretion onto a non-rotating star. The accretion process unfolds with intricate 3-D structures driven by various mechanisms. First, the disc develops filaments at the magnetospheric…
NASA's NICER telescope has recently provided evidence for non-dipolar magnetic field structures in rotation-powered millisecond pulsars. These stars are assumed to have gone through a prolonged accretion spin-up phase, begging the question…
We present results of global three-dimensional (3D) magnetohydrodynamic (MHD) simulations of accretion onto magnetized stars where both the magnetic and rotational axes of the star are tilted about the rotational axis of the disc. We…
We perform two-dimensional, axisymmetric, magnetohydrodynamic simulations of the collapse of a rotating star of 40 Msun and in the light of the collapsar model of gamma-ray burst. Considering two distributions of angular momentum, up to…
We study the general-relativistic dynamics of matter being accreted onto and ejected by a magnetised and nonrotating neutron star. The dynamics is followed in the framework of fully general relativistic magnetohydrodynamics (GRMHD) within…
Aims. A realistic model of magnetic linkage between a central object and its accretion disk is a prerequisite for understanding the spin history of stars and stellar remnants. To this end, we aim to provide an analytic model in agreement…
We investigate accretion onto a central star, with the size, rotation rate, and magnetic dipole of a young stellar object, to study the flow pattern (velocity and density) of the fluid within and outside of the disc. We perform resistive…
Millisecond x-ray pulsars have weak magnetic dipole moments of $\sim 10^{16}$\,T\,m$^3$ compared to ordinary X-ray pulsars with dipole moments of $10^{20}$\,T\,m$^3$. For this reason a surrounding accretion disc can extend closer to the…
We perform resistive MHD simulations of accretion disk with alpha-viscosity, accreting onto a rotating star endowed with a magnetic dipole. We find backflow in the presence of strong magnetic field and large resistivity, and probe for the…
We present global 3D MHD simulations of geometrically thin but unstratified accretion disks in which a near Keplerian disk rotates between two bounding regions with initial rotation profiles that are stable to the MRI. The inner region…
The stability of an accretion disc surrounding a millisecond pulsar is analysed from an energetic point of view, using magnetohydrodynamic simulations that consider realistic disc structures and a variety of magnetic field inclination…
Disk accretion to rotating stars with complex magnetic fields is investigated using full three-dimensional magnetohydrodynamic (MHD) simulations. The studied magnetic configurations include superpositions of misaligned dipole and quadrupole…
The appearance and time variability of accreting millisecond X-ray pulsars (hereafter AMXPs, e.g. Wijnands & van der Klis 1998) depends strongly on the accretion rate, the effective viscosity and the effective magnetic diffusivity of the…
We model gas inflow patterns onto circumstellar disks and the evolution of the pseudodisk using three-dimensional resistive MHD simulations. Starting from a prestellar core without turbulence and with a misalignment between the initial…
We discuss basic features of steady accretion disk morphology around magnetized compact astrophysical objects. A comparison between the standard model of accretion based on visco-resistive MHD and the plasma instabilities, like ballooning…
We performed 2D and full 3D magnetohydrodynamic simulations of disk accretion to a rotating star with an aligned or misaligned dipole magnetic field. We investigated the rotational equilibrium state and derived from simulations the ratio…
Accreting neutron stars can power a wide range of astrophysical phenomena including short- and long-duration gamma-ray bursts, ultra-luminous X-ray sources, and X-ray binaries. Numerical simulations are a valuable tool for studying the…