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Related papers: Magnetic fields in galaxies: I. Radio disks in loc…

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A three-dimensional (3D) MHD model is applied to simulate the evolution of a large-scale magnetic field in a barred galaxy possessing a gaseous halo extending to about 2.8 kpc above the galactic plane. As the model input we use a…

Astrophysics · Physics 2009-11-07 K. Otmianowska-Mazur , D. Elstner , M. Soida , M. Urbanik

The activity of magnetars is believed to be powered by colossal magnetic energy reservoirs. We sketch an evolutionary picture in which internal field evolution in magnetars generates a twisted corona, form which energy may be released…

High Energy Astrophysical Phenomena · Physics 2016-06-22 S. K. Lander

The small-scale turbulent dynamo is a key mechanism for amplifying galactic magnetic fields, yet the resulting field morphology remains poorly understood. Using 3D driven turbulence simulations across a range of compressibilities,…

Astrophysics of Galaxies · Physics 2026-03-25 Sasi M. Behara , Amit Seta

Nonresonant current instability was identified by Bell (2004) as an important mechanism for magnetic field amplification in supernova remnants. In this paper we focus on studying the nonlinear stage of this instability using the…

Astrophysics of Galaxies · Physics 2014-06-06 Andrey Beresnyak , Hui Li

A variety of observations suggest that magnetic fields are present in all galaxies and galaxy clusters. These fields are characterized by a modest strength (10^{-7}-10^{-5} G) and huge spatial scale (~Mpc). It is generally assumed that…

Astrophysics · Physics 2008-11-26 Lawrence M. Widrow

Observational and theoretical work has now established that the fossil fields of magnetic massive stars are surviving remnants from an earlier event, or an earlier evolutionary phase. However, many important questions remain regarding the…

Solar and Stellar Astrophysics · Physics 2020-01-30 Pınar Cerrahoğlu , Véronique Petit , Zsolt Keszthelyi , Alexandre David-Uraz

We review current ideas on the origin of galactic and extragalactic magnetic fields. We begin by summarizing observations of magnetic fields at cosmological redshifts and on cosmological scales. These observations translate into constraints…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Lawrence M. Widrow , Dongsu Ryu , Dominik Schleicher , Kandaswamy Subramanian , Christos G. Tsagas , Rudolf A. Treumann

We investigate the magnetic field evolution in a series of galaxy minor mergers using the N-body/smoothed particle hydrodynamics (SPH) code \textsc{Gadget}. The simulations include the effects of radiative cooling, star formation and…

Astrophysics of Galaxies · Physics 2015-05-30 Annette Geng , Hanna Kotarba , Florian Bürzle , Klaus Dolag , Federico Stasyszyn , Alexander Beck , Peter Nielaba

We perform cosmological, hydrodynamic simulations of magnetic fields in galaxy clusters. The computational code combines the special-purpose hardware Grape for calculating gravitational interaction, and smooth-particle hydrodynamics for the…

Astrophysics · Physics 2007-05-23 Klaus Dolag , Matthias Bartelmann , Harald Lesch

We use three dimensional magnetohydrodynamic simulations to study the structure of the boundary layer between an accretion disc and a non-rotating, unmagnetized star. Under the assumption that cooling is efficient, we obtain a narrow but…

Astrophysics · Physics 2009-11-07 Philip J. Armitage

We argue that the recently reported Kolmogorov-like magnetic turbulence spectrum in the cool core of the Hydra A galaxy cluster can be understood by kinetic energy injection by active galaxies that drives a turbulent non-helical magnetic…

Astrophysics · Physics 2009-11-11 T. A. Ensslin , C. Vogt

Rotation and magnetism are increasingly recognized as important phenomena in stellar evolution. Surface magnetic fields from a few to $20{,}000\,$G have been observed and models have suggested that magnetohydrodynamic transport of angular…

Solar and Stellar Astrophysics · Physics 2018-04-04 Leo G. Quentin , Christopher A. Tout

We present a set of global, self-consistent N-body/SPH simulations of the dynamic evolution of galactic discs with gas and including magnetic fields. We have implemented a description to follow the evolution of magnetic fields with the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 H. Kotarba , H. Lesch , K. Dolag , T. Naab , P. H. Johansson , F. A. Stasyszyn

Both observations and modelling of magnetic fields in the diffuse interstellar gas of spiral galaxies are well developed but the theory has been confronted with observations for only a handful of individual galaxies. There is now sufficient…

Astrophysics of Galaxies · Physics 2015-06-23 Cameron Van Eck , Jo-Anne Brown , Anvar Shukurov , Andrew Fletcher

Supernovae are the dominant energy source for driving turbulence within the interstellar plasma. Until recently, their effects on magnetic field amplification in disk galaxies remained a matter of speculation. By means of self-consistent…

Astrophysics · Physics 2009-11-13 Oliver Gressel , Udo Ziegler , Detlef Elstner , Günther Rüdiger

Observations reveal the presence of supermassive black holes (SMBH) as early as ~700 million years after the Big Bang. Their formation path is still subject to current debate. We explore the influence of magnetic fields, which are strongly…

Astrophysics of Galaxies · Physics 2019-06-12 Philipp Grete , Muhammad A. Latif , Dominik R. G. Schleicher , Wolfram Schmidt

We study the evolution of galactic magnetic fields using 3D smoothed particle magnetohydrodynamics (SPMHD) simulations of galaxies with an imposed spiral potential. We consider the appearance of reversals of the field, and amplification of…

Astrophysics of Galaxies · Physics 2016-09-07 C. L. Dobbs , D. J. Price , A. R. Pettitt , M. R. Bate , T. Tricco

Magnetic fields significantly influence the evolution of protoplanetary disks and the formation of planets, following the predictions of numerous magnetohydrodynamic (MHD) simulations. However, these predictions are yet observationally…

Earth and Planetary Astrophysics · Physics 2016-11-09 Gesa H. -M. Bertrang , Mario Flock , Sebastian Wolf

Early-type stars show a bimodal distribution of magnetic field strengths, with some showing very strong fields ($\gtrsim 1\,\mathrm{kG}$) and others very weak fields ($\lesssim 10\,\mathrm{G}$). Recently, we proposed that this reflects the…

Solar and Stellar Astrophysics · Physics 2021-12-22 Adam S. Jermyn , Matteo Cantiello

We consider the accretion process in a disk with magnetic fields that are dragged in from the interstellar medium by gravitational collapse. Two diffusive processes are at work in the system: (1) "viscous" torques exerted by turbulent and…

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