Conveners
MHD Processes Near Compact Objects: Block 1
- Sergey Moiseenko (Space Research Institute, Moscow, Russia)
Description
The topic of the parallel session includes different processes in strong gravitational fields, where a magnetic field and plasma properties play an important, and even decisive role. It includes magneto-rotational processes in supernova and supernova remnants, gamma-ray bursts and jets; processes which take place near pulsars, magnetorotational instability; structure and dynamics of accretion disks inside the ergosphere, and close to the last stable orbit of the Kerr black hole, gravitation lensing in plasma, etc.
Astrophysical problems such as modelling of core-collapse supernovae, collapses of protostellar clouds as well as other processes, involving collapsing matter, deal with regions (e.g. protostars, protoneutron stars), where a speed of sound has much larger values, than in remaining parts of a computational domain. A time-step in explicit numerical schemes, thus, has to be bounded according to...
Ultraluminous X-ray sources (ULXs) are very bright, off-nuclear, point sources with luminosity exceeding the standard Eddington limit of a stellar-mass black hole (BH). The existing physical scenarios to explain their unusual large luminosity and spectral nature are either super-Eddington accretion around a stellar-mass BH or the existence of the missing class of intermediate-mass BH (IMBH)....
Analytical expressions are obtained for four tensors of kinetic coefficients from the solution of the Boltzmann equation by the Chapman-Enskog method in the 3-polynomial approximation, taking into account electron-electron collisions for the case of nondegenerate electrons in a magnetic field.
For strongly degenerate electrons, asymptotically accurate analytical expressions for the thermal...
Abstract:
We attempt to address the old problem of accretion flow: the origin of turbulence and hence transport of angular momentum in accretion flows. We undertake the problem by introducing an extra force in Orr-Sommerfeld and Squire equations along with the Coriolis force mimicking the local region of the accretion disk. Subsequently, we solve the equations with the WKB approximation...
Many neutron stars propagate through the interstellar medium with supersonic velocities, and their magnetospheres interact with the interstellar medium (ISM), forming bow shocks and magnetotails.
Using numerical MHD simulations, we investigated the propagation of a magnetized neutron stars through a non-uniform ISM, the interaction of the magnetospheres with the ISM and the influence of ISM...
We study geometrically thick perfect-fluid tori with constant specific angular momentum, so-called "Polish doughnuts", orbiting deformed compact objects with a quadrupole moment. More specifically, we consider two different asymptotically flat, static and axisymmetric vacuum solutions to Einstein's field equation with a non-zero quadrupole moment, the q-metric and the Erez-Rosen spacetime. It...
In this presentation the white dwarf close binaries AE Aquarii and AR Sco are investigated to search for signatures of particle acceleration and associated non-thermal emission. A detailed investigation of the total Fermi-LAT data base reveal signatures of pulsed gamma-ray emission in AE Aquarii, which mimics earlier reports of transient burst-like pulsed TeV gamma-ray emission reported from...
Accretion discs surrounding neutron stars, black stars and white dwarfs play an important role in theoretical astrophysics. Their evolution is closely connected with the magnetic field structure. Nowadays there are different approaches for studying the magnetic field and the mechanism of its growth. However, we can conclude that it is highly likely that the origin of the magnetic field of the...
