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Related papers: Radiation from sub-Larmor scale magnetic fields

200 papers

We present a theory of ultrarelativistic collisionless shocks based on the relativistic kinetic two-stream instability. We demonstrate that the shock front is unstable to the generation of small-scale, randomly tangled magnetic fields.…

Astrophysics · Physics 2009-11-06 Mikhail V. Medvedev

Fast radio bursts (FRBs) are bright, short-duration radio transients with very high brightness temperatures implying highly coherent emission. We suggest that the FRBs are caused by the self-focusing of an electron beam interacting with an…

High Energy Astrophysical Phenomena · Physics 2020-03-18 Mustafa Doğan , Kazım Yavuz Ekşi

The mechanisms that generate "seed" magnetic fields in our Universe and that amplify them throughout cosmic time remain poorly understood. By means of fully-kinetic particle-in-cell simulations of turbulent, initially unmagnetized plasmas,…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-09 L. Sironi , L. Comisso , R. Golant

A new magnetic field generation mechanism in electrostatic shocks is found, which can produce fields with magnetic energy density as high as 0.01 of the kinetic energy density of the flows on time scales $ \tilde \, 10^4 \,…

Plasma Physics · Physics 2015-06-22 A. Stockem , T. Grismayer , R. A. Fonseca , L. O. Silva

Astrophysical and high-energy-density laboratory plasmas often have large-amplitude, sub-Larmor-scale electromagnetic fluctuations excited by various kinetic-streaming or anisotropy-driven instabilities. The Weibel (or the filamentation)…

High Energy Astrophysical Phenomena · Physics 2017-05-10 Mikhail V. Medvedev

We develop the theory of jitter radiation from GRB shocks containing small-scale magnetic fields and propagating at an angle with respect to the line of sight. We demonstrate that the spectra vary considerably: the low-energy photon index,…

Astrophysics · Physics 2009-11-13 Mikhail V. Medvedev

Radiation from GRBs in the prompt phase, flares and an afterglow is thought to be produced by accelerated electrons in magnetic fields. Such emission may be produced at collisionless shocks of baryonic outflows or at reconnection sites (at…

High Energy Astrophysical Phenomena · Physics 2009-06-25 Mikhail V. Medvedev

The origin of the observed large scale magnetic fields in the Universe is a mystery. The seed of these magnetic fields has been attributed to physical process in the early universe. In this work we provide a mechanism for the generation of…

High Energy Physics - Phenomenology · Physics 2016-09-12 Abhishek Atreya , Soma Sanyal

The interaction of strong electromagnetic fields with plasma generates radiation accompanied by a recoil force, which can significantly alter the plasma dynamics. In this work, we investigate the development of anisotropic momentum…

Plasma Physics · Physics 2025-09-25 Haidar Al-Naseri

We consider radiation emitted by the jitter mechanism in a Blandford-McKee self-similar blastwave. We assume the magnetic field configuration throughout the whole blastwave meets the condition for the emission of jitter radiation and we…

Astrophysics · Physics 2009-11-13 Brian J. Morsony , Jared C. Workman , Davide Lazzati , Mikhail V. Medvedev

Magnetic field amplification by relativistic streaming plasma instabilities is central to a wide variety of high-energy astrophysical environments as well as to laboratory scenarios associated with intense lasers and electron beams. We…

Plasma Physics · Physics 2021-06-02 J. R. Peterson , S. Glenzer , F. Fiuza

Plasmas with electromagnetic fields turbulent at sub-Larmor-scales are a feature of a wide variety of high-energy-density environments, and are essential to the description of many astrophysical/laboratory plasma phenomena. Radiation from…

Plasma Physics · Physics 2015-09-16 Brett D. Keenan , Alexander L. Ford , Mikhail V. Medvedev

Collisionless shocks can be produced as a result of strong magnetic fields in a plasma flow, and therefore are common in many astrophysical systems. The Weibel instability is one candidate mechanism for the generation of sufficiently strong…

The linear growth rate and saturation level of magnetic fields for Weibel instabilities driven by ion temperature anisotropy, defined as $\alpha=(T_\perp/T_\parallel)-1$ where $T_\perp$ and $T_\parallel$ are ion temperatures perpendicular…

Astrophysics · Physics 2009-11-11 Chuang Ren , Eric G. Blackman , Wen-fai Fong

We have investigated particle acceleration and emission from shocks and shear flows associated with an unmagnetized relativistic jet plasma propagating into an unmagnetized ambient plasma. Strong electro-magnetic fields are generated in the…

High Energy Astrophysical Phenomena · Physics 2014-12-23 K. -I. Nishikawa , P. Hardee , I. Dutan , B. Zhang , A. Meli , E. J. Choi , K. Min , J. Niemiec , Y. Mizuno , M. Medvedev , A. Nordlund , J. T. Frederiksen , H. Sol , M. Pohl , D. Hartmann

We study the long term evolution of magnetic fields generated by an initially unmagnetized collisionless relativistic $e^+e^-$ shock. Our 2D particle-in-cell numerical simulations show that downstream of such a Weibel-mediated shock,…

Astrophysics · Physics 2009-06-23 Philip Chang , Anatoly Spitkovsky , Jonathan Arons

The external forward shock emitting the gamma-ray burst (GRB) afterglow is collisionless, and it is mediated by the Weibel instability which generates the magnetic field. The GRB afterglow shows that the magnetic field in the large…

High Energy Astrophysical Phenomena · Physics 2020-01-08 Sara Tomita , Yutaka Ohira , Ryo Yamazaki

We present an investigation for the generation of intense magnetic fields in dense plasmas with an anisotropic electron Fermi-Dirac distribution. For this purpose, we use a new linear dispersion relation for transverse waves in the…

Plasma Physics · Physics 2015-05-13 F. Haas , P. K. Shukla , B. Eliasson

We discuss a mechanism for intense electromagnetic wave emission at an astrophysical relativistic shock in a magnetized collisionless plasma. At the magnetized shock, the particle reflection by a compressed magnetic field of the shock…

High Energy Astrophysical Phenomena · Physics 2019-02-19 Takanobu Amano , Masanori Iwamoto , Yosuke Matsumoto , Masahiro Hoshino

The onset and evolution of magnetic fields in laboratory and astrophysical plasmas is determined by several mechanisms, including instabilities, dynamo effects and ultra-high energy particle flows through gas, plasma and interstellar-media.…

Plasma Physics · Physics 2015-05-20 A. Flacco , J. Vieira , A. Lifschitz , F. Sylla , S. Kahaly , M. Veltcheva , L. O. Silva , V. Malka