English
Related papers

Related papers: The Cosmic Battery Revisited

200 papers

In some Seyfert Galaxies, the hard X-rays that produce fluorescent emission lines are thought to be generated in a hot corona that is compact and located at only a few gravitational radii above the supermassive black hole. We consider the…

High Energy Astrophysical Phenomena · Physics 2019-06-14 Yajie Yuan , Anatoly Spitkovsky , Roger D. Blandford , Dan R. Wilkins

We discuss generation of magnetic field from cosmological perturbations. We consider the evolution of three component plasma (electron, proton and photon) evaluating the collision term between elecrons and photons up to the second order.…

It is shown that the standard cosmological model predicts {\it ab initio} generation of large-scale but very small-amplitude cosmic magnetic fields at the epoch of recombination of the primeval plasma. Matter velocities dominated by…

Astrophysics · Physics 2007-05-23 Craig J. Hogan

Using mean-field theory, we compute the evolution of the magnetic field in a cylinder with outer perfectly conducting boundaries, an imposed axial magnetic and electric field. The thus injected magnetic helicity in the system can be…

Plasma Physics · Physics 2012-03-27 Koen Kemel , Axel Brandenburg , Hantao Ji

The magneto-rotational instability (MRI) is the most likely mechanism for transportation of angular momentum and dissipation of energy within hot, ionized accretion discs. This instability is produced through the interactions of a…

High Energy Astrophysical Phenomena · Physics 2021-12-08 Oscar M. Pimentel , P. Chris Fragile , F. D. Lora-Clavijo , Bridget Ierace , Deepika Bollimpalli

Our aim in this note is to compare a recent explanation of the galactic X pattern in Faraday Rotation (XRM), to that produced by the advection part of the classical dynamo.We find that the characteristic X magnetic field polarization in the…

Astrophysics of Galaxies · Physics 2022-02-09 R N Henriksen

In this work we consider an extended electromagnetic theory in which the scalar state which is usually eliminated by means of the Lorenz condition is allowed to propagate. This state has been shown to generate a small cosmological constant…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-01 Jose Beltran Jimenez , Antonio L. Maroto

The flow of a matter, accreting onto a magnetized neutron star, is accompanied by an electric current. The closing of the electric current occurs in the crust of a neutron stars in the polar region across the magnetic field. But the…

High Energy Astrophysical Phenomena · Physics 2016-04-01 Ya. N. Istomin , I. A. Semerikov

We address the role of large scale magnetic stress in the angular momentum transport, as well as the formation of different kinds of magnetic barrier in geometrically thick, optically thin, vertically averaged 1.5-dimensional advective…

High Energy Astrophysical Phenomena · Physics 2019-08-28 Tushar Mondal , Banibrata Mukhopadhyay

Recent rotation measure observations of a dozen or so galaxy clusters have revealed a surprisingly large amount of magnetic fields, whose estimated energy and flux are, on average, $\sim 10^{58}$ ergs and $\sim 10^{41}$ G cm$^2$,…

Astrophysics · Physics 2007-05-23 Stirling A. Colgate , Hui Li

We present a mechanism to create vortices in a plasma via gravitational dragging behind rotating cosmic string loops. The vortical motions create magnetic fields by means of the Harrison-Rees mechanism; the fields are further enhanced…

Astrophysics · Physics 2009-06-23 Thorsten Battefeld

We consider the hypothesis that galactic magnetic fields are primordial. We also discuss the various objections to this hypothesis. We assume that there was a magnetic field present in the galactic plasma before the galaxy formed. After the…

Astrophysics · Physics 2016-08-30 Armando M. Howard , Russell M. Kulsrud

We present an instability occurring in the inner part of disks threaded by a moderately strong vertical (poloidal) magnetic field. Its mechanism is such that a spiral density wave in the disk, driven by magnetic stresses (rather than…

Astrophysics · Physics 2007-05-23 M. Tagger , R. Pellat

The paper considers the dynamics of the plasma generated by the explosive-emission cells of the cathode spot of a vacuum arc in a magnetic field. It is shown that the expansion of the (high-density) plasma in a transverse magnetic field may…

Plasma Physics · Physics 2019-05-22 M. M. Tsventoukh

We analyze three-dimensional magnetohydrodynamic (MHD) simulations of a nonradiative accretion flow around a black hole using a pseudo-Newtonian potential. The flow originates from a torus initially centered at 100 gravitational…

Astrophysics · Physics 2009-11-07 John F. Hawley , Steven A. Balbus

We investigate the build-up of the galactic dynamo and subsequently the origin of a magnetic driven outflow. We use a setup of an isolated disc galaxy with a realistic circum-galactic medium (CGM). We find good agreement of the galactic…

Astrophysics of Galaxies · Physics 2020-04-01 Ulrich P. Steinwandel , Klaus Dolag , Harald Lesch , Benjamin P. Moster , Andreas Burkert , Almudena Prieto

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

We present a detailed characterization of the structure and evolution of differentially rotating plasmas driven on the MAGPIE pulsed-power generator (1.4 MA peak current, 240 ns rise-time). The experiments were designed to simulate physics…

We carried out global three-dimensional resistive magnetohydrodynamic simulations of galactic gaseous disks to investigate how the galactic magnetic fields are amplified and maintained. We adopt a steady axisymmetric gravitational potential…

Astrophysics · Physics 2009-11-11 Hiromitsu Nishikori , Mami Machida , Ryoji Matsumoto

I study the generation and evolution of magnetic fields in the plasma surrounding a rotating black hole. Attention is focused on effects of the gravitomagnetic potential. The gravitomagnetic force appears as battery term in the generalized…

Astrophysics · Physics 2007-05-23 Ramon Khanna