Related papers: Accreting Schwarzschild-like compact object: Plasm…
The electron beam-plasma system is ubiquitous in the space plasma environment. Here, using a Darwin particle-in-cell method, the excitation of electrostatic and whistler instabilities by a gyrating electron beam is studied in support of…
An extremely compact object (ECO) is defined as a quantum object without horizon, whose radius is just a small distance $s$ outside its Schwarzschild radius. We show that any ECO of mass $M$ in $d+1$ dimensions with $s\ll…
The shocked wave created on the accretion disk after different physical phenomena (accretion flows with pressure gradients, star-disk interaction etc.) may be responsible observed Quasi Periodic Oscillations (QPOs) in $X-$ray binaries. We…
Accretion onto compact objects plays a central role in high energy astrophysics. In these environments, both general relativistic and plasma effects may have significant impacts upon the propagation of photons. We present a full general…
Propagation of the finite amplitude electromagnetic wave through the partially spin-polarized degenerate plasmas leads to the instability. The instability happens at the interaction of the electromagnetic wave with the small frequency…
The twin-peak high-frequency quasi-periodic oscillations (HF QPOs), observed in the power spectra of low-mass X-ray binaries, might carry relevant clues about the physics laws reigning close to a compact object. Their frequencies are…
The self-consistent problem of the wave and particle spectrum is formulated and solved for acceleration of particles in a homogeneous magnetic field that varies periodically with time. It follows from the obtained solutions that when…
Motivated by electromagnetic-field confinement due to plasma near accreting black holes, we continue our exploration of the linear dynamics of an electromagnetic field propagating in curved spacetime in the presence of plasma by including…
We examine the spectrum of a massive scalar particle interacting with the strong gravitational field of a static, spherically symmetric object which is not quite massive enough to be a black hole. As was found in the case of massless…
We demonstrate that generically an accretion disk around a compact object could have a new type of instability in that the accretion flow need not be symmetric with respect to the equatorial plane even when matter is supplied symmetrically…
Two-dimensional accretion flows near black holes have been investigated by time-dependent hydrodynamical calculations. We assume that the flow is axisymmetric and that radiative losses of internal energy are negligible, so that the disc is…
We have performed Monte Carlo simulations of Compton upscattering of low-energy photons in an accretion disk around a Schwarzschild black hole. The photons gain energy from the rotational motion of the electrons in the disk. The…
Aims. EXor-type objects are protostars that display powerful UV-optical outbursts caused by intermittent and powerful events of magnetospheric accretion. These objects are not yet well investigated and are quite difficult to characterize.…
We investigate the transmission of scalar, electromagnetic, and linearized odd-parity gravitational waves in a static spacetime characterized by a spherical distribution of matter in the form of thin concentric equidistant shells of equal…
Kappa distributions are ubiquitous in space and astrophysical poorly collisional plasmas, such as the solar wind, suggesting that microscopic and macroscopic properties of these non-equilibrium plasmas are highly conditioned by the…
We numerically examine centrifugally supported shock waves in 2D rotating accretion flows around a stellar-mass (10M_sun) and a supermassive (10^6M_sun) black holes over a wide range of input accretion rates of 10^7 >\dot M/\dot…
A pair plasma in hidrostatic equilibrium near the horizon of a Schwarzschild black hole is an exact state. In this work, we show that an exact non--hidrostatic equilibrium state can be sustained for a pair plasma, in which its constituents…
The ambiguity involved in the use of Maxwell's equation particularly in electron plasmas is discussed. It is pointed out that in the slow time scale perturbations the displacement current is ignored but it does not imply that the electron…
The accretion of matter onto celestial bodies like black holes and neutron stars is a natural phenomenon that releases up to $40\%$ of the matter's rest-mass energy, which is considered a source of radiation. In active galactic nuclei and…
We derive the mutual coherence function of an electron beam propagating through a static or dynamic Coulomb-disordered medium and show that its decay introduces an intrinsic coherence-reduction mechanism relevant for electron microscopy in…