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相关论文: Dynamics of Mesoscale Magnetic Field in Diffusive …

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The generation of large-scale magnetic fields is generically accompanied by the more rapid growth of small-scale fields. The growing Lorentz force due to these fields back reacts on the turbulence to saturate the mean-field and small-scale…

天体物理学 · 物理学 2009-11-07 Kandaswamy Subramanian

We investigate effects of upstream density fluctuations on the diffusive shock acceleration by Monte Carlo simulations. The simulations show that particles are reaccelerated in the shock downstream region by a sound wave generated at the…

高能天体物理现象 · 物理学 2020-07-08 Shota L. Yokoyama , Yutaka Ohira

Convectively driven dynamos with rotation generating magnetic fields on scales large compared with the scale of the turbulent eddies are being reviewed. It is argued that such fields can be understood as the result of an alpha effect.…

太阳与恒星天体物理 · 物理学 2011-08-19 A. Brandenburg , P. J. Käpylä , M. J. Korpi

Super-Alfv\'enic turbulence is widespread in astrophysical environments, including molecular clouds and the diffuse plasma of galaxy clusters. At large scales, magnetic fields play only a minor dynamical role; however, for sufficiently…

星系天体物理 · 物理学 2025-12-24 A. Lazarian , Yue Hu , D. Pogosyan

Radio, X-ray, and gamma-ray observations provide us with strong evidence of particle acceleration to multi-TeV energies in various astrophysical sources. Diffusive shock acceleration is one of the most successful models explaining the…

天体物理学 · 物理学 2009-11-13 G. Vannoni , S. Gabici , F. A. Aharonian

The dynamic processes of magnetic reconnection and turbulence cause magnetic islands/flux-ropes generation. The in-situ observations suggest that the coalescence or/and contraction of magnetic islands are responsible to the charged particle…

空间物理 · 物理学 2016-11-18 Anil Raghav , Zubair Shaikh

The study of dynamo action in astrophysical objects classically involves two timescales: the slow diffusive one and the fast advective one. We investigate the possibility of field amplification on an intermediate timescale associated with…

经典物理 · 物理学 2009-11-13 Emmanuel Dormy , David Gerard-Varet

We consider a recently discovered class of instabilities, driven by cosmic ray streaming, in a variety of environments. We show that although these instabilities have been discussed primarily in the context of supernova driven interstellar…

星系天体物理 · 物理学 2014-11-20 Ellen G. Zweibel , John E. Everett

The effect of a magnetic field on the linear phase of the advective-acoustic instability is investigated, as a first step toward a magnetohydrodynamic (MHD) theory of the stationary accretion shock instability taking place during stellar…

太阳与恒星天体物理 · 物理学 2014-11-20 Jerome Guilet , Thierry Foglizzo

Magnetic dissipation through decay of Alfven waves in the magnetar magnetosphere is discussed. Transport of magnetic fields in the star leads to dissipation of the magnetic energy through either direct internal heating or transferring of…

天体物理学 · 物理学 2009-06-23 Qinghuan Luo

The electroweak phase transition, if proceeding through nucleation and growth of bubbles, should generate large scale turbulent flow, which in turn generates magnetic turbulence and hence magnetic fields on the scale of turbulent flow. We…

高能物理 - 唯象学 · 物理学 2009-10-28 Gordon Baym , Dietrich Bödeker , Larry McLerran

We have performed extensive two-dimensional magnetohydrodynamic simulations to study the amplification of magnetic fields when a supernova blast wave propagates into a turbulent interstellar plasma. The blast wave is driven by injecting…

高能天体物理现象 · 物理学 2015-06-03 Fan Guo , Shengtai Li , Hui Li , Joe Giacalone , J. R. Jokipii , David Li

The solar atmosphere is structured and inhomogeneous both horizontally and vertically. The omnipresence of coronal magnetic loops implies gradients of the equilibrium plasma quantities like the density, magnetic field and temperature. These…

太阳与恒星天体物理 · 物理学 2010-07-30 J. Vranjes , S. Poedts

Synchrotron radio emission from non-relativistic jets powered by massive protostars has been reported, indicating the presence of relativistic electrons and magnetic fields of strength ~0.3-5 mG. We study diffusive shock acceleration and…

高能天体物理现象 · 物理学 2021-03-31 Anabella Araudo , Marco Padovani , Alexandre Marcowith

We present new generation mechanisms of magnetic fields in supernova remnant shocks propagating to partially ionized plasmas in the early universe. Upstream plasmas are dissipated at the collisionless shock, but hydrogen atoms are not…

高能天体物理现象 · 物理学 2022-09-08 Shuhei Kashiwamura , Yutaka Ohira

We numerically study the diffusion and scattering of cosmic rays (CRs) together with their acceleration processes in the framework of the modern understanding of magnetohydrodynamic (MHD) turbulence. Based on the properties of compressible…

高能天体物理现象 · 物理学 2023-11-17 Nana Gao , Jianfu Zhang

A relativistic collisionless shock propagating into an unmagnetized medium leaves behind a strong large-scale magnetic field. This seems to follow from two assumptions: (i) GRB afterglows are explained by synchrotron emission of a…

天体物理学 · 物理学 2009-11-06 Andrei Gruzinov

Magnetic field amplification is needed to accelerate cosmic cays to PeV energies in supernova remants. Escaping cosmic rays trigger a return current in the plasma that drives a non-resonant hybrid instability. We run simulations in which we…

高能天体物理现象 · 物理学 2012-09-17 K. M. Schure , A. R. Bell

A two-field Hamiltonian gyrofluid model for kinetic Alfv\'en waves retaining ion finite Larmor radius corrections and parallel magnetic field fluctuations is used to study direct turbulent cascades from the MHD to the sub-ion scales. For…

空间物理 · 物理学 2022-06-13 T. Passot , P. L. Sulem , D. Laveder

We discuss the influence of large scale cosmic magnetic fields on the propagation of hadronic cosmic rays above 10^19 eV based on large scale structure simulations. Our simulations suggest that rather substantial deflection up to several…

天体物理学 · 物理学 2009-11-10 Guenter Sigl , Francesco Miniati , Torsten Ensslin