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Related papers: Galactic dynamo simulations

200 papers

Mean-field dynamo theory has important applications in solar physics and galactic magnetism. We discuss some of the many turbulence effects relevant to the generation of large-scale magnetic fields in the solar convection zone. The…

Solar and Stellar Astrophysics · Physics 2023-11-23 Axel Brandenburg , Detlef Elstner , Youhei Masada , Valery Pipin

Magnetic fields have been included in cosmological simulations of galaxy formation only recently, due to advances in numerical techniques and a better understanding of the galaxy formation physics. In this paper, we develop a new subgrid…

Astrophysics of Galaxies · Physics 2022-05-13 Yuankang Liu , Michael Kretschmer , Romain Teyssier

The role of turbulence in astrophysical environments and its interplay with magnetic fields is still highly debated. In this lecture, we will discuss this issue in the framework of dynamo processes. We will first present a very brief…

Solar and Stellar Astrophysics · Physics 2015-06-12 E. M. de Gouveia Dal Pino , R. Santos-Lima , G. Kowal , D. Falceta-Gonçalves

We report first results of first global galactic-scale CR-MHD simulations of cosmic-ray-driven dynamo. We investigate the dynamics of magnetized interstellar medium (ISM), which is dynamically coupled with the cosmic-ray (CR) gas. We assume…

Astrophysics of Galaxies · Physics 2009-11-05 Michał Hanasz , Dominik Wóltański , Kacper Kowalik

The turbulent dynamo may explain the origin of cosmic magnetism. While the exponential amplification of magnetic fields has been studied for incompressible gases, little is known about dynamo action in highly-compressible, supersonic…

Astrophysics of Galaxies · Physics 2014-12-05 Christoph Federrath , Jennifer Schober , Stefano Bovino , Dominik R. G. Schleicher

Magnetic fields are ubiquitous in the Universe. Extragalactic disks, halos and clusters have consistently been shown, via diffuse radio-synchrotron emission and Faraday rotation measurements, to exhibit magnetic field strengths ranging from…

The small-scale turbulent dynamo is an important process contributing to the cosmic magnetization. In partially ionized astrophysical plasmas, the dynamo growth of magnetic energy strongly depends on the coupling state between ions and…

Astrophysics of Galaxies · Physics 2019-02-20 Siyao Xu , Sudip K. Garain , Dinshaw S. Balsara , A. Lazarian

The origin and the magnitude of the inter-galactic magnetic field is of primordial importance in the global picture of magnetic field evolution, as it is considered to be the missing link between galactic magnetic fields and cluster…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Yohan Dubois , Romain Teyssier

We present self-consistent cosmological magnetohydrodynamic (MHD) simulations that simultaneously follow the formation of a galaxy cluster and the magnetic field ejection by an active galactic nucleus (AGN). We find that the magnetic fields…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-27 Hao Xu , Hui Li , David C. Collins , Shengtai Li , Michael L. Norman

The nature and origin of turbulence and magnetic fields in the intergalactic space are important problems that are yet to be understood. We propose a scenario in which turbulent flow motions are induced via the cascade of the vorticity…

Astrophysics · Physics 2009-11-13 Dongsu Ryu , Hyesung Kang , Jungyeon Cho , Santabrata Das

Using the test-field method for nearly irrotational turbulence driven by spherical expansion waves it is shown that the turbulent magnetic diffusivity increases with magnetic Reynolds numbers. Its value levels off at several times the rms…

Astrophysics of Galaxies · Physics 2010-11-05 Axel Brandenburg , Fabio Del Sordo

In this paper we further advance the study of magnetic field amplification in the interstellar medium that was started in Balsara et al (2004, Paper I). We show that the flux growth rate is comparable to the rate of magnetic energy growth…

Astrophysics · Physics 2009-11-10 D. S. Balsara , J. S. Kim

In previous galactic dynamo theories of the origin of the magnetic field in our galaxy, the subject of flux-freezing has been omitted. As a consequence, the equation of mass flow has generally also been omitted, particularly in the halo…

Astrophysics of Galaxies · Physics 2015-12-23 Russell M. Kulsrud

Cluster media are dynamical, not static; observational evidence suggests they are turbulent. High-resolution simulations of the intracluster media (ICMs) and of idealized, similar media help us understand the complex physics and…

Cosmology and Nongalactic Astrophysics · Physics 2011-01-24 T. W. Jones , David H. Porter , Dongsu Ryu , Jungyeon Cho

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

The existence of large-scale dynamos in rigidly rotating turbulent convection without shear is studied using three-dimensional numerical simulations of penetrative rotating compressible convection. We demonstrate that rotating convection in…

Astrophysics · Physics 2011-02-11 P. J. Käpylä , M. J. Korpi , A. Brandenburg

The Interstellar Medium (ISM) is a complex, multi-phase system, where the history of the stars occurs. The processes of birth and death of stars are strongly coupled to the dynamics of the ISM. The observed chaotic and diffusive motions of…

Astrophysics of Galaxies · Physics 2011-02-02 D. Falceta-Goncalves

It is shown that a number of key observations of the Galactic ISM can be understood, if it is treated as a highly compressible and turbulent medium energized predominantly by supernova explosions (and stellar winds). We have performed…

Astrophysics · Physics 2009-11-11 Dieter Breitschwerdt , Miguel A. de Avillez

In order to determine the circumstances under which isolated SNRs are capable of rising into and enriching the thick disk and galactic halo, simulations of supernova remnants are performed with the FLASH magnetohydrodynamic code. We…

Astrophysics · Physics 2008-11-26 E. A. Raley , R. L. Shelton , T. Plewa

The gaseous media of galaxy clusters and cosmic filaments, which constitute most of the baryonic matter in the universe, is highly dynamic. It is also probably turbulent, although the turbulence properties are poorly known. The gas is…

Cosmology and Nongalactic Astrophysics · Physics 2011-08-08 T. W. Jones , D. H. Porter , D. Ryu , J. Cho