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Related papers: Particle Diffusion and Acceleration in Magnetorota…

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Understanding the dynamics of material objects advected by turbulent flows is a long standing question in fluid dynamics. In this perspective article we focus on the characterization of the statistical properties of non-interacting…

Fluid Dynamics · Physics 2024-03-18 Yaning Fan , Cheng Wang , Linfeng Jiang , Chao Sun , Enrico Calzavarini

This paper reports on 3D numerical simulations of dynamics and thermodynamics in the diffuse ISM. Our models are local, account for sheared galactic rotation, magnetic fields, and realistic cooling, and resolve scales ~1-200 pc. This…

Astrophysics · Physics 2009-11-11 Robert A. Piontek , Eve C. Ostriker

Activity of the nuclei of galaxies and stellar mass systems involving disk accretion to black holes is thought to be due to (1) a small-scale turbulent magnetic field in the disk (due to the magneto-rotational instability or MRI) which…

High Energy Astrophysical Phenomena · Physics 2009-08-05 R. V. E. Lovelace , D. M. Rothstein , G. S. Bisnovatyi-Kogan

This research was motivated by the recent observations indicating very strong magnetic fields at some supernova remnant shocks, which suggests in-situ generation of magnetic turbulence. The dissertation presents a numerical model of…

High Energy Astrophysical Phenomena · Physics 2009-04-27 Andrey Vladimirov

Particle acceleration and magnetic field amplification in relativistic shocks propagating in inhomogeneous media are investigated by three-dimensional magnetohydrodynamical (MHD) simulations and test-particle simulations. The MHD…

High Energy Astrophysical Phenomena · Physics 2024-06-27 Kanji Morikawa , Yutaka Ohira , Takumi Ohmura

We use a global magnetohydrodynamic simulation of a geometrically thin accretion disk to investigate the locality and detailed structure of turbulence driven by the magnetorotational instability (MRI). The model disk has an aspect ratio $H…

High Energy Astrophysical Phenomena · Physics 2015-05-28 Kris Beckwith , Philip J. Armitage , Jacob B. Simon

The aim of this paper is to investigate the properties of accretion disks threaded by a weak vertical magnetic field, with a particular focus on the interplay between MHD turbulence driven by the magnetorotational instability (MRI) and…

High Energy Astrophysical Phenomena · Physics 2015-06-11 Sebastien Fromang , Henrik N. Latter , Geoffroy Lesur , Gordon I. Ogilvie

We present the results of local, vertically stratified, radiation MHD shearing box simulations of MRI turbulence appropriate for the hydrogen ionizing regime of dwarf nova and soft X-ray transient outbursts. We incorporate the…

High Energy Astrophysical Phenomena · Physics 2014-04-29 Shigenobu Hirose , Omer Blaes , Julian H. Krolik , Matthew S. B. Coleman , Takayoshi Sano

One of the main features of astrophysical shocks is their ability to accelerate particles to extremely high energies. The leading acceleration mechanism, the diffusive shock acceleration is reviewed. It is demonstrated that its efficiency…

Astrophysics · Physics 2009-11-06 M. A. Malkov , P. H. Diamond

Context: Typical space plasmas contain spatially and temporally variable turbulent electromagnetic fields. Understanding the transport of energetic particles and the acceleration mechanisms for charged particles is an important goal of…

High Energy Astrophysical Phenomena · Physics 2013-06-17 R. C. Tautz , I. Lerche , F. Kruse

Turbulent motion driven by the magnetorotational instability (MRI) is believed to provide an anomalous viscosity strong enough to account for observed accretion rates in protostellar accretion disks. In the first of two papers, we perform…

Solar and Stellar Astrophysics · Physics 2015-06-19 Wayne O'Keeffe , Turlough P. Downes

The dynamics of inertial particles in turbulence is modelled and investigated by means of direct numerical simulation of an axisymmetrically expanding homogeneous turbulent strained flow. This flow can mimic the dynamics of particles close…

Fluid Dynamics · Physics 2023-07-19 Chung-min Lee , Ármann Gylfason , Prasad Perlekar , Federico Toschi

Relativistic magnetically dominated turbulence is an efficient engine for particle acceleration in a collisionless plasma. Ultrarelativistic particles accelerated by interactions with turbulent fluctuations form non-thermal power-law…

Plasma Physics · Physics 2023-06-14 Cristian Vega , Stanislav Boldyrev , Vadim Roytershteyn

We study the acceleration of electrons and protons interacting with localized, multiple, small-scale dissipation regions inside an evolving, turbulent active region. The dissipation regions are Unstable Current Sheets (UCS), and in their…

Astrophysics · Physics 2009-11-10 L. Vlahos , H. Isliker , F. Lepreti

Due to its ubiquitous presence, turbulence is often invoked to explain the origin of nonthermal particles in astrophysical sources of high-energy emission. With particle-in-cell simulations, we study decaying turbulence in…

High Energy Astrophysical Phenomena · Physics 2018-12-21 Luca Comisso , Lorenzo Sironi

3D Magnetohydrodynamic (MHD) resistive simulations have highlighted the significance of ubiquitous turbulence to drive fast reconnection. It has been demonstrated that particle acceleration via reconnection in 3D magnetized flows, where…

High Energy Astrophysical Phenomena · Physics 2025-04-08 E. M. de Gouveia Dal Pino , J. C. Ramirez-Rodriguez , T. Medina-Torrejon , G. H. Vicentin , L. Passos Reis

This letter investigates the transport properties of MHD turbulence induced by the magnetorotational instability at large Reynolds numbers Re when the magnetic Prandtl number Pm is larger than unity. Three MHD simulations of the…

High Energy Astrophysical Phenomena · Physics 2016-12-07 Sebastien Fromang

Planets are born in protostellar disks, which are now observed with enough resolution to address questions about internal gas flows. Candidates for driving the flows include magnetic forces, but ionization state estimates suggest much of…

We present a scaling law that predicts the values of the stresses obtained in numerical simulations of saturated MRI-driven turbulence in non-stratified shearing boxes. It relates the turbulent stresses to the strength of the vertical…

Astrophysics · Physics 2009-11-13 Martin E. Pessah , Chi-kwan Chan , Dimitrios Psaltis

The transport of angular momentum in the outward direction is the fundamental requirement for accretion to proceed in an accretion disc. This objective can be achieved if the accretion flow is turbulent. Instabilities are one of the sources…

Astrophysics of Galaxies · Physics 2014-11-21 Mradul Sharma