Related papers: Particle Heating in Advection-Dominated Accretion …
Using only the assumption that all interactions between particles in an accretion flow are electromagnetically mediated, it is shown that the time to establish equipartition between ions and electrons is shorter than the characteristic…
Magnetohydrodynamic (MHD) turbulence is a ubiquitous dynamical state of astrophysical plasmas and a primary agent in the redistribution, dissipation, and conversion of energy into particle populations. Yet turbulence is still most often…
Dynamics of clumps within a magnetized advection dominated accretion flow is investigated by solving the collisionless Boltzmann equation and considering the drag force due to the relative velocity between the clumps and the gas. Toroidal…
We study the heat conduction of a cold, thermal cloud in a highly asymmetric trap. The cloud is axially hydrodynamic, but due to the asymmetric trap radially collisionless. By locally heating the cloud we excite a thermal dipole mode and…
In the innermost regions of low-luminosity accretion flows, including Sgr A* at the center of our Galaxy, the frequency of Coulomb collisions is so low that the plasma is two-temperature, with the ions substantially hotter than the…
The effect of a possible hydrodynamical wind on the nature of hot accretion disk solutions is studied. It is found that the advection dominated branch, in the presence of a wind, maintains the self-similar solution for the disk structure…
Observations of the hot gas surrounding Sgr A* and a few other nearby galactic nuclei imply electron and proton mean free paths comparable to the gas capture radius: hot accretion likely proceeds under weakly-collisional conditions in these…
Unraveling the origin of proton beams and ion Bernstein waves is important to understanding kinetic dissipation in the solar wind. Here we focus on their generation mechanisms, rather than their well-studied roles in instabilities and…
We solve for the structure of a hot accretion disc with unsaturated thermal Comptonisation of soft photons and with advection, generalizing the classical model of Shapiro et al. The upper limit on the accretion rate due to advection…
The heating, acceleration, and pitch-angle scattering of charged particles by MHD turbulence are important in a wide range of astrophysical environments, including the solar wind, accreting black holes, and galaxy clusters. We simulate the…
We study of the effect of turbulence on diffusion processes within magnetized medium. While we exemplify our treatment with heat transfer processes, our results are quite general and are applicable to different processes, e.g. diffusion of…
Fast, counter-streaming plasma outflows drive magnetic field amplification, plasma heating, and particle acceleration in numerous astrophysical environments, from supernova remnant shocks to active galactic nuclei jets. Understanding how,…
The set of equations for magnetohydrodynamic (MHD) waves in a shear flow is consecutively derived. The proposed scenario involves the presence of a self-sustained turbulence and magnetic field. In the framework of Langevin--Burgers approach…
Scaling laws for the transport and heating of trace heavy ions in low-frequency, magnetized plasma turbulence are derived and compared with direct numerical simulations. The predicted dependences of turbulent fluxes and heating on ion…
The gas temperature in protoplanetary disks (PPDs) is determined by a combination of irradiation heating and accretion heating, with the latter conventionally attributed to turbulent dissipation. However, recent studies have suggested that…
Nonthermal acceleration of particles in magnetohydrodynamic (MHD) turbulence plays a central role in a wide variety of astrophysical sites. This physics is addressed here in the context of a strong turbulence, composed of coherent…
The effect of compressibility in charged particle energization by magnetohydrodynamic (MHD) fields is studiedin the context of test particle simulations. This problem is relevant to the solar wind and the solar corona due to the…
We propose that inward, subsonic flows arise from the local dissipation of turbulent motions in molecular clouds. Such "turbulent cooling flows" may account for recent observations of spatially extended inward motions towards dense cores.…
How thermal equilibrium is determined in a weakly collisional plasma is a fundamental question in plasma physics. This letter shows that the turbulence driven by the magnetic curvature and density gradient tends to equilibrate the…
We study the effects of anisotropic thermal conduction on low-collisionality, astrophysical plasmas using two and three-dimensional magnetohydrodynamic simulations. For weak magnetic fields, dilute plasmas are buoyantly unstable for either…