Related papers: A global model of the magnetorotational instabilit…
The extraordinary energetic activity of magnetars is usually explained in terms of dissipation of a huge internal magnetic field of the order of $10^{15-16}$G. How such a strong magnetic field can originate during the formation of a neutron…
A differentially rotating hypermassive neutron star (HMNS) is a metastable object which can be formed in the merger of neutron-star binaries. The eventual collapse of the HMNS into a black hole is a key element in generating the physical…
Though usually treated in isolation, the magnetorotational and gravitational instabilities (MRI and GI) may coincide at certain radii and evolutionary stages of protoplanetary discs and active galactic nuclei. Their mutual interactions…
The magnetorotational instability (MRI) is an important process in sufficiently ionized accretion disks, as it can create turbulence that acts as an effective viscosity, mediating angular momentum transport. Due to its local nature, it is…
Current models of magnetars require extremely strong magnetic fields to explain their observed quiescent and bursting emission, implying that the field strength within the star's outer crust is orders of magnitude larger than the dipole…
The magneto-rotational instability (MRI) is widely believed to play a central role in generating large-scale, poloidal magnetic fields during binary neutron star mergers. However, the few simulations that begin with a weak seed magnetic…
Jetted astrophysical phenomena with black hole (BH) engines, including binary mergers, jetted tidal disruption events, and X-ray binaries, require a large-scale vertical magnetic field for efficient jet formation. However, a dynamo…
We report first results of first global galactic-scale CR-MHD simulations of cosmic-ray-driven dynamo. We investigate the dynamics of magnetized interstellar medium (ISM), which is dynamically coupled with the cosmic-ray (CR) gas. We assume…
Irregular galaxies are usually smaller and less massive than their spiral, S0, and elliptical counterparts. Radio observations indicate that a magnetic field is present in irregular galaxies whose value is similar to that in spiral…
The turbulence driven by gravitational instabilities (GIs) can amplify magnetic fields in massive gaseous disks. This GI dynamo may appear in young circumstellar disks, whose weak ionization challenges other amplification routes, as well as…
Magneto-rotational instability (MRI) is an important instability mechanism for rotating flows with magnetic fields. In particular, when the strength of the magnetic field tends to zero, the stability criterion for rotating flows is…
Radio observations show that magnetic fields are present in dwarf irregular galaxies (dIrr) and its strength is comparable to that found in spiral galaxies. Slow rotation, weak shear and shallow gravitational potential are the main features…
Magnetars are isolated young neutron stars characterized by the most intense magnetic fields known in the universe. The origin of their magnetic field is still a challenging question. In situ magnetic field amplification by dynamo action is…
Global three dimensional magnetohydrodynamic (MHD) simulations of turbulent accretion disks are presented which start from fully equilibrium initial conditions in which the magnetic forces are accounted for and the induction equation is…
We have investigated evolution of magneto-rotational instability (MRI) in protoplanetary disks that have radially non-uniform magnetic field such that stable and unstable regions coexist initially, and found that a zone in which the disk…
The magneto-rotational instability (MRI) - which is due to an interplay between a sheared background and the magnetic field - is commonly considered a key ingredient for developing and sustaining turbulence in the outer envelope of binary…
We investigate the impact of strong initial magnetic fields in core-collapse supernovae of non-rotating progenitors by simulating the collapse and explosion of a 16.9 Msun star for a strong- and weak-field case assuming a twisted-torus…
We study the magnetorotational instability (MRI) using nonmodal stability techniques. Despite the spectral instability of many forms of the MRI, this proves to be a natural method of analysis that is well-suited to deal with the…
We performed the first numerical simulations of magnetorotational instability from a sub-magnetar-class seed magnetic field in core collapse supernovae. As a result of axisymmetric ideal MHD simulations, we found that the magnetic field is…
We investigate the linear growth and vertical structure of the magnetorotational instability (MRI) in weakly ionised, stratified accretion discs. The magnetic field is initially vertical and dust grains are assumed to have settled towards…