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相关论文: Turbulence-induced magnetic fields in shock precur…

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Cosmic-ray streaming instabilities at supernova shocks are discussed in the quasilinear diffusion formalism which takes into account the feedback effect of wave growth on the cosmic ray streaming motion. In particular, the nonresonant…

高能天体物理现象 · 物理学 2015-05-13 Qinghuan Luo , Don Melrose

In this paper we show that the Universe is already strongly magnetized at very early epochs during cosmic evolution. Our calculations are based on the efficient amplification of weak magnetic seed fields, which are unavoidably present in…

宇宙学与河外天体物理 · 物理学 2014-05-09 Jacques M. Wagstaff , Robi Banerjee , Dominik Schleicher , Guenter Sigl

We consider the diffusive shock acceleration in interstellar bubbles created by powerful stellar winds of supernova progenitors. Under the moderate stellar wind magnetization the bubbles are filled by the strongly magnetized low density…

高能天体物理现象 · 物理学 2018-02-14 V. N. Zirakashvili , V. S. Ptuskin

We explore the amplification of magnetic fields in the high-redshift Universe. For this purpose, we perform high-resolution cosmological simulations following the formation of primordial halos with \sim10^7 M_solar, revealing the presence…

A nonresonant cosmic-ray-current-driven instability may operate in the shock precursors of young supernova remnants and be responsible for magnetic-field amplification, plasma heating and turbulence. Earlier simulations demonstrated…

高能天体物理现象 · 物理学 2018-01-08 Oleh Kobzar , Jacek Niemiec , Martin Pohl , Artem Bohdan

We present results of 2D and 3D PIC simulations of magnetic turbulence production by isotropic cosmic-ray ions drifting upstream of SNR shocks. The studies aim at testing recent predictions of a strong amplification of short wavelength…

天体物理学 · 物理学 2009-11-13 Jacek Niemiec , Martin Pohl , Thomas Stroman , and Ken-Ichi Nishikawa

The interstellar medium (ISM) is permeated by magnetic fields that affect gas dynamics and star formation. These fields correlate with supernova (SN)-driven turbulence, but whether the scaling is universal across galaxy properties, ISM…

星系天体物理 · 物理学 2026-03-31 Davide Belfiori , Sergio Martin-Alvarez , Enrique Lopez-Rodriguez , Rosita Paladino

We investigate the diffusive shock acceleration in the presence of the non-resonant streaming instability introduced by Bell (2004). The numerical MHD simulations of the magnetic field amplification combined with the analytical treatment of…

天体物理学 · 物理学 2009-11-13 V. N. Zirakashvili , V. S. Ptuskin

Magnetic fields pervade the entire Universe and affect the formation and evolution of astrophysical systems from cosmological to planetary scales. The generation and dynamical amplification of extragalactic magnetic fields through cosmic…

宇宙学与河外天体物理 · 物理学 2016-04-27 F. Rincon , F. Califano , A. A. Schekochihin , F. Valentini

Afterglows of gamma-ray bursts are believed to require magnetic fields much stronger than that of the compressed pre-shock medium. As an alternative to microscopic plasma instabilities, we propose amplification of the field by macroscopic…

天体物理学 · 物理学 2009-11-13 Lorenzo Sironi , Jeremy Goodman

The process of diffusive shock acceleration relies on the efficacy with which hydromagnetic waves can scatter charged particles in the precursor of a shock. The growth of self-generated waves is driven by both resonant and non-resonant…

天体物理学 · 物理学 2009-11-13 B. Reville , S. O'Sullivan , P. Duffy , J. G. Kirk

The amplification of primordial magnetic fields via a small-scale turbulent dynamo during structure formation might be able to explain the observed magnetic fields in galaxy clusters. The magnetisation of more tenuous large-scale structures…

宇宙学与河外天体物理 · 物理学 2015-06-22 F. Vazza , M. Brüggen , C. Gheller , P. Wang

In this work we report a numerical study of the cosmic magnetic field amplification due to collisionless plasma instabilities. The collisionless magnetohydrodynamic equations derived account for the pressure anisotropy that leads, in…

宇宙学与河外天体物理 · 物理学 2015-08-06 D. Falceta-Goncalves , G. Kowal

The role of turbulence in astrophysical environments and its interplay with magnetic fields is still highly debated. In this lecture, we will discuss this issue in the framework of dynamo processes. We will first present a very brief…

太阳与恒星天体物理 · 物理学 2015-06-12 E. M. de Gouveia Dal Pino , R. Santos-Lima , G. Kowal , D. Falceta-Gonçalves

We demonstrate that cosmic rays form filamentary structures in the precursors of supernova remnant shocks due to their self-generated magnetic fields. The cosmic-ray filamentation results in the growth of a long wavelength instability, and…

高能天体物理现象 · 物理学 2015-05-30 B. Reville , A. R. Bell

Even though the interstellar medium (ISM) of star-forming galaxies has been known to have a multiphase structure (broadly hot, warm, and cold phases) since the 1970s, how magnetic fields differ between the ISM phases is still unknown. Using…

星系天体物理 · 物理学 2024-10-08 Amit Seta

The problem of the cosmic ray origin is discussed in connection with their acceleration in supernova remnant shocks. The diffusive shock acceleration mechanism is reviewed and its potential to accelerate particles to the maximum energy of…

天体物理学 · 物理学 2007-05-23 P. H. Diamond , M. A. Malkov

Magnetic fields are widely observed in the Universe in virtually all astrophysical objects, from individual stars to entire galaxies, even in the intergalactic medium, but their specific generation has long been debated. Due to the…

星系天体物理 · 物理学 2017-11-08 Michael Rieder , Romain Teyssier

We present a parameter study of the magnetohydrodynamical dynamo driven by cosmic rays in the interstellar medium (ISM) focusing on the efficiency of magnetic field amplification and the issue of energy equipartition between magnetic,…

天体物理学 · 物理学 2015-05-13 Michał Hanasz , Katarzyna Otmianowska-Mazur , Grzegorz Kowal , Harald Lesch

Magnetic fields are a dynamically important component of the turbulent interstellar medium (ISM) of star-forming galaxies. These magnetic fields are due to a dynamo action, which is a process of converting turbulent kinetic energy to…

星系天体物理 · 物理学 2022-06-01 Amit Seta , Christoph Federrath