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We develop a model based on 3D mean-field MHD for the generation of large scale magnetic fields in fully convective objects like low-mass stars, brown dwarfs and possibly gaseous planets. The dynamo process is of alpha^2 type and thus…

Astrophysics · Physics 2016-08-30 Gilles Chabrier , Manfred Kueker

Magnetic fields are ubiquitously observed in the interstellar medium (ISM) of present-day star-forming galaxies with dynamically relevant energy densities. Using three-dimensional magneto-hydrodynamic (MHD) simulations of the supernova (SN)…

Galaxy clusters host a hot, diffuse plasma with poorly understood viscosity and magnetic field amplification. Astrophysical plasmas are often modeled with magnetohydrodynamics (MHD), but low collision rates in environments like the…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-17 S. Adduci Faria , R. Santos-Lima , E. M. de Gouveia Dal Pino

Magnetic fields play an important role in astrophysical accretion discs, and in the interstellar and intergalactic medium. They drive jets, suppress fragmentation in star-forming clouds and can have a significant impact on the accretion…

Plasma Physics · Physics 2016-12-30 Christoph Federrath

The merger of binary neutron stars (BNSs) can lead to large amplifications of the magnetic field due to the development of turbulence and instabilities in the fluid, such as the Kelvin-Helmholtz shear instability, which drive small-scale…

High Energy Astrophysical Phenomena · Physics 2015-09-09 Bruno Giacomazzo , Jonathan Zrake , Paul Duffell , Andrew I. MacFadyen , Rosalba Perna

Magnetic fields in several astrophysical objects are amplified and maintained by a dynamo mechanism, which is the conversion of the turbulent kinetic energy to magnetic energy. A dynamo that amplifies magnetic fields at scales $<$ the…

Astrophysics of Galaxies · Physics 2021-09-27 Amit Seta , Christoph Federrath

We have performed extensive two-dimensional magnetohydrodynamic simulations to study the amplification of magnetic fields when a supernova blast wave propagates into a turbulent interstellar plasma. The blast wave is driven by injecting…

High Energy Astrophysical Phenomena · Physics 2015-06-03 Fan Guo , Shengtai Li , Hui Li , Joe Giacalone , J. R. Jokipii , David Li

We show that under very general conditions, cluster plasmas threaded by weak magnetic fields are subject to very fast growing plasma instabilities driven by the anisotropy of the plasma pressure (viscous stress) with respect to the local…

Astrophysics · Physics 2008-11-26 A. A. Schekochihin , S. C. Cowley , R. M. Kulsrud , G. W. Hammett , P. Sharma

The origin of cosmic magnetic fields is widely attributed to the amplification of weak seed fields by turbulent dynamos. However, a critical understanding gap remains between the microscopic generation of these seeds and the macroscopic…

Plasma Physics · Physics 2026-02-12 X. Liu , D. Wu , J. Zhang

Magnetic fields are observed beyond the peripheries of optically detected galactic discs, while numerical models of their origin and the typical magnitudes are still absent. Previously, studies of galactic dynamo have avoided considering…

Astrophysics of Galaxies · Physics 2014-09-05 E. Mikhailov , A. Kasparova , D. Moss , R. Beck , D. Sokoloff , A. Zasov

(abridged) We investigate the possibility to recognize the magnetic field structures in nearby galaxies and to test the cosmological evolution of their large- and small-scale magnetic fields with the SKA and its precursors. We estimate the…

Cosmology and Nongalactic Astrophysics · Physics 2010-02-18 T. G. Arshakian , R. Stepanov , R. Beck , M. Krause , D. Sokoloff , P. Frick

Galactic dynamo models have generally relied on input parameters that are very challenging to constrain. We address this problem by developing a model that uses observable quantities as input: the galaxy rotation curve, the surface…

Astrophysics of Galaxies · Physics 2024-04-04 Luke Chamandy , Rion Glenn Nazareth , Gayathri Santhosh

We present a dynamical model of supernova feedback which follows the evolution of pressurised bubbles driven by supernovae in a multi-phase interstellar medium (ISM). The bubbles are followed until the point of break-out into the halo,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Claudia del P. Lagos , Cedric G. Lacey , Carlton M. Baugh

Additional physics beyond standard hydrodynamics is needed to fully model the intracluster medium (ICM); however, as we move to more sophisticated models, it is important to consider the role of magnetic fields and the way the fluid…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-04 Hilary Egan , Brian W. O'Shea , Eric Hallman , Jack Burns , Hao Xu , David Collins , Hui Li , Michael L. Norman

We present simulations of isolated disc galaxies in a realistic environment performed with the Tree-SPMHD-Code Gadget-3. Our simulations include a spherical circum-galactic medium (CGM) surrounding the galactic disc, motivated by…

Astrophysics of Galaxies · Physics 2018-11-28 Ulrich P. Steinwandel , Marcus C. Beck , Alexander Arth , Klaus Dolag , Benjamin P. Moster , Peter Nielaba

Supernova (SN) explosions deposit prodigious energy and momentum in their environments, with the former regulating multiphase thermal structure and the latter regulating turbulence and star formation rates in the interstellar medium (ISM).…

Astrophysics of Galaxies · Physics 2015-06-23 Chang-Goo Kim , Eve C. Ostriker

We present non-radiative, cosmological zoom-simulations of galaxy cluster formation with magnetic fields and (anisotropic) thermal conduction of one very massive galaxy cluster with a mass at redshift zero that corresponds to…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-20 Ulrich P. Steinwandel , Ludwig M. Boess , Klaus Dolag , Harald Lesch

We conduct global galactic--scale magnetohydrodynamical (MHD) simulations of the cosmic--ray driven dynamo. We assume that exploding stars deposit small--scale, randomly oriented, dipolar magnetic fields into the differentially rotating…

Astrophysics of Galaxies · Physics 2009-11-13 Michał Hanasz , Dominik Wóltański , Kacper Kowalik , Rafał Pawłaszek

We introduce the LYRA project, a new high resolution galaxy formation model built within the framework of the cosmological hydro-dynamical moving mesh code AREPO. The model resolves the multi-phase interstellar medium down to 10 K. It forms…

Astrophysics of Galaxies · Physics 2021-02-26 Thales A. Gutcke , Rüdiger Pakmor , Thorsten Naab , Volker Springel

We investigate the evolution of magnetic fields in galaxy clusters starting from constant primordial fields using highly resolved ($\approx \rm 4 ~kpc$) cosmological MHD simulations. The magnetic fields in our sample exhibit amplification…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-27 Paola Domínguez-Fernández , Franco Vazza , Marcus Brüggen , Gianfranco Brunetti