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Related papers: Bulk Comptonization by Turbulence in Accretion Dis…

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Accretion disks are observed in young stars, cataclysmic variables, binary X-ray sources et al. Accretion disk theory was first developed as a theory with the local heat balance, where the whole energy produced by a viscous heating was…

Astrophysics · Physics 2007-05-23 G. S. Bisnovatyi-Kogan

We calculated the bolometric images of relativistic slim disks during radiation-pressure-driven thermal instability. When the mass-accretion rate exceeds the critical one, an inner region of the standard accretion disk bursts to change to a…

Astrophysics · Physics 2007-05-23 Akihiro Kawata , Ken-ya Watarai , Jun Fukue

Two-dimensional numerical simulations of an accretion flow in a close binary system are performed by solving the Euler equations with radiative transfer. In the present study, the specific heat ratio is assumed to be constant while…

Astrophysics · Physics 2009-11-07 Jun'ichi Sato , Keisuke Sawada , Naofumi Ohnishi

We review numerical simulations of MHD turbulence. The last decade has witnessed fundamental advances both in the technical capabilities of direct numerical simulation, and in our understanding of key physical processes. Magnetic fields tap…

Astrophysics · Physics 2007-05-23 Steven A. Balbus , John F. Hawley

Advection-dominated, high-temperature, quasi-spherical accretion flow onto a compact object, recently considered by a number of authors, assume that the dissipation of turbulent energy of the flow heats the ions and that the dissipated…

Astrophysics · Physics 2009-10-30 G. S. Bisnovatyi-Kogan , R. V. E. Lovelace

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…

Plasma Physics · Physics 2026-05-25 Chuanpeng Hou , Huirong Yan , Siqi Zhao

The mechanisms governing the transition to turbulence in natural convection boundary layers along strongly heated vertical walls remain neither very clear nor well understood, because of the lack of experiments and the difficulties of…

Fluid Dynamics · Physics 2008-12-23 Thierry De Larochelambert

An analytical model for a turbulent clumpy gas disk is presented where turbulence is maintained by the energy input due to supernovae. Expressions for the disk parameters, global filling factors, molecular fractions, and star formation…

Astrophysics · Physics 2009-11-07 B. Vollmer , T. Beckert

(Abridged) Context. Massive stars form in magnetized and turbulent environments, and are often located in stellar clusters. Their accretion mechanism, as well as the origin of their system's stellar multiplicity are poorly understood. Aims.…

Solar and Stellar Astrophysics · Physics 2021-08-11 R. Mignon-Risse , M. González , B. Commerçon , Joakim Rosdahl

We perform numerical simulations of magneto-rotational instability in a local patch of accretion disk in which radiation pressure exceeds gas pressure. Such conditions may occur in the central regions of disks surrounding compact objects in…

Astrophysics · Physics 2007-05-23 N. J. Turner , J. M. Stone , T. Sano

We investigate the effects of subsonic turbulence on a normal mode of oscillation [a possible origin of the high-frequency quasi-periodic oscillations (HFQPOs) within some black hole accretion disks]. We consider perturbations of a…

High Energy Astrophysical Phenomena · Physics 2021-10-27 Robert V. Wagoner , Celia R. Tandon

Turbulence and turbulent mixing in natural fluids begins with big bang turbulence powered by spinning combustible combinations of Planck particles and Planck antiparticles. Particle prograde accretions on a spinning pair releases 42% of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Carl H. Gibson

We evaluate whether dissipation of turbulence injected into hot cluster atmospheres by jets and bubbles can offset radiative cooling flows. No trends are found between atmospheric velocity dispersion, $\sigma_v$, and either the ratio of…

High Energy Astrophysical Phenomena · Physics 2026-04-22 B. R. McNamara , A. C. Fabian , H. R. Russell , P. E. J. Nulsen , A. Simionescu , A. Majumder , E. D. Miller , A. Sarkar

Turbulent high-energy astrophysical systems often feature asymmetric energy injection: for instance, Alfven waves propagating from an accretion disk into its corona. Such systems are "imbalanced": the energy fluxes parallel and…

High Energy Astrophysical Phenomena · Physics 2021-12-22 Amelia Hankla , Vladimir Zhdankin , Gregory Werner , Dmitri Uzdensky , Mitchell Begelman

A fundamental assumption in our understanding of disks is that when the Toomre Q>>1, the disk is stable against fragmentation into self-gravitating objects (and so cannot form planets via direct collapse). But if disks are turbulent, this…

Earth and Planetary Astrophysics · Physics 2014-11-13 Philip F. Hopkins , Jessie L. Christiansen

A dissipation rate, which grows faster than any power of the wave number in Fourier space, may be scaled to lead a hydrodynamic system {\it actually} or {\it potentially} converge to its Galerkin truncation. Actual convergence we name for…

Chaotic Dynamics · Physics 2009-09-29 Jian-Zhou Zhu , Mark Taylor

Thermal conduction between a cool accretion disk and a hot inner corona can result in either evaporation of the disk or condensation of the hot corona. At low mass accretion rates, evaporation dominates and can completely remove the inner…

High Energy Astrophysical Phenomena · Physics 2015-05-20 B. F. Liu , C. Done , Ronald E. Taam

The relationship between a decaying strong turbulence and kinetic instabilities in a slowly expanding plasma is investigated using two-dimensional (2-D) hybrid expanding box simulations. We impose an initial ambient magnetic field…

We study particle clustering in a temperature stratified turbulence with small finite correlation time. It is shown that the temperature stratified turbulence strongly increases the degree of compressibility of particle velocity field. This…

Fluid Dynamics · Physics 2014-11-19 Tov Elperin , Nathan Kleeorin , Michael Liberman , Igor Rogachevskii

Massive disk fragmentation has been suggested to be one of the mechanisms leading to the formation of giant planets. While it has been heavily studied in quiescent hydrodynamic disks, the effect of MHD turbulence arising from the…

Astrophysics · Physics 2009-11-11 Sebastien Fromang