English
Related papers

Related papers: Magnetic field generation by the stationary accret…

200 papers

The origin of the magnetic field in galaxies is an open question in astrophysics. Several mechanisms have been proposed related, in general, with the generation of small seed fields amplified by a dynamo mechanism. In general, these…

Astrophysics · Physics 2009-10-30 O. D. Miranda , M. Opher , R. Opher

Extremely strong magnetic fields of the order of $10^{15}\,{\rm G}$ are required to explain the properties of magnetars, the most magnetic neutron stars. Such a strong magnetic field is expected to play an important role for the dynamics of…

High Energy Astrophysical Phenomena · Physics 2017-10-25 Jerome Guilet , Ewald Mueller , Hans-Thomas Janka , Tomasz Rembiasz , Martin Obergaulinger , Pablo Cerda-Duran , Miguel-Angel Aloy

We present a set of three-dimensional, global, general relativistic radiation magnetohydrodynamic simulations of thin, radiation-pressure-dominated accretion disks surrounding a non-rotating, stellar-mass black hole. The simulations are…

High Energy Astrophysical Phenomena · Physics 2022-11-09 Bhupendra Mishra , P. Chris Fragile , Jessica Anderson , Aidan Blankenship , Hui Li , Krzysztof Nalewajko

We present very-high-resolution 1D MHD simulations of the late-stage supernova remnants (SNR). In the post-adiabatic stage the magnetic field has an important and significant dynamical effect on the shock dynamics, the flow structure, and…

High Energy Astrophysical Phenomena · Physics 2018-07-18 O. Petruk , T. Kuzyo , S. Orlando , M. Pohl , M. Miceli , F. Bocchino , V. Beshley , R. Brose

A relatively modest value of the initial rotation of the iron core, a period of ~ 6-31 s, will give a very rapidly rotating protoneutron star and hence strong differential rotation with respect to the infalling matter. Under these…

Astrophysics · Physics 2007-05-23 Shizuka Akiyama , J. Craig Wheeler

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

Evidence is accumulating suggesting that collisionless shocks in supernova remnants (SNRs) can amplify the interstellar magnetic field to hundreds of microgauss or even milli-gauss levels, as recently claimed for SNR RX J1713.7-3946. If…

Astrophysics · Physics 2009-11-13 Donald C. Ellison , Andrey Vladimirov

Synchrotron emission from a supernova necessitates a magnetic field, but it is unknown how strong the relevant magnetic fields are, and what mechanism generates them. In this study, we perform high-resolution numerical gas dynamics…

High Energy Astrophysical Phenomena · Physics 2016-02-26 Paul Duffell , Daniel Kasen

The explosion mechanism of core-collapse supernovae has not been fully understood yet but multi-dimensional fluid instabilities such as standing accretion shock instability (SASI) and convection are now believed to be crucial for shock…

High Energy Astrophysical Phenomena · Physics 2017-02-08 Kazuya Takahashi , Wakana Iwakami , Yu Yamamoto , Shoichi Yamada

Several lines of evidence suggest that protogalactic and galactic environments manage to grow magnetic field very rapidly. This makes the theoretical problem of achieving rapid growth of magnetic fields in such environments difficult.…

Astrophysics · Physics 2009-11-10 D. S. Balsara , J. S. Kim , M. M. Mac Low , G. Mathews

We present a theory for the generation of mesoscale ($kr_{g}\ll 1$, where $r_{g}$ is the cosmic ray gyroradius) magnetic fields during diffusive shock acceleration. The decay or modulational instability of resonantly excited Alfven waves…

Astrophysics · Physics 2008-11-26 P. H. Diamond , M. A. Malkov

This paper examines the generation of seed magnetic fields due to the growth of cosmological perturbations. In the radiation era, different rates of scattering from photons induce local differences in the ion and electron density and…

Astrophysics · Physics 2008-11-26 E. R. Siegel , J. N. Fry

We investigate axisymmetric steady solutions of (magneto)hydrodynamics equations that describe approximately accretion flows through a standing shock wave and discuss the effects of rotation and magnetic field on the revival of the stalled…

High Energy Astrophysical Phenomena · Physics 2019-02-27 Kotaro Fujisawa , Hirotada Okawa , Yu Yamamoto , Shoichi Yamada

The maximum magnetic field strength generated by Weibel-type plasma instabilities is estimated for typical conditions in the interstellar medium. The relevant kinetic dispersion relations are evaluated by conducting a parameter study both…

High Energy Astrophysical Phenomena · Physics 2015-06-16 R. C. Tautz , J. Triptow

I present a scenario by which an accretion flow with alternating angular momentum sense on to a newly born neutron star in core collapse supernovae (CCSNe) efficiently amplifies magnetic fields and by that launches jets. The accretion flow…

High Energy Astrophysical Phenomena · Physics 2019-07-24 Noam Soker

We propose the mean field dynamo model for the generation of strongest magnetic fields, $B\sim 10^{15}\,{\rm G}$, in a neutron star (NS) accounting for the chiral magnetic effect (CME) driven by the shock in a supernova (SN) progenitor of…

High Energy Astrophysical Phenomena · Physics 2020-04-08 Maxim Dvornikov , V. B. Semikoz , D. D. Sokoloff

Relativistic, spherically symmetric configurations consisting of a gravitating magnetized anisotropic fluid are studied. For such configurations, we obtain static equilibrium solutions with an axisymmetric, poloidal magnetic field produced…

General Relativity and Quantum Cosmology · Physics 2015-03-03 Vladimir Folomeev , Vladimir Dzhunushaliev

We perform 3D radiation-magnetohydrodynamic simulations of the evolution of the fallback debris after a tidal disruption event. We focus on studying the effects of magnetic fields on the formation and early evolution of the accretion flow.…

High Energy Astrophysical Phenomena · Physics 2025-10-28 Maria Renee Meza , Xiaoshan Huang , Shane W. Davis , Yan-Fei Jiang

We have determined the physical mechanism responsible for the plasma instabilities, which was first found by Ramani and Laval (1978), associated with anisotropic velocity distributions induced by the temperature gradient in which there are…

Astrophysics · Physics 2009-11-10 Nobuhiro Okabe , Makoto Hattori

In rotating neutron stars the existence of the Coriolis force allows the presence of the so-called Rossby oscillations (r-modes) which are know to be unstable to emission of gravitational waves. Here, for the first time, we introduce the…

High Energy Astrophysical Phenomena · Physics 2014-11-20 Carmine Cuofano , Alessandro Drago