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Related papers: Small-Scale Dynamo Action in Primordial Halos

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We investigate the structure of magnetic field amplified by turbulent velocity fluctuations, in the framework of the kinematic Kazantsev-Kraichnan model. We consider Kolmogorov distribution of velocity fluctuations, and assume that both…

Astrophysics · Physics 2010-01-15 Leonid Malyshkin , Stanislav Boldyrev

Supernovae are known to be the dominant energy source for driving turbulence in the interstellar medium. Yet, their effect on magnetic field amplification in spiral galaxies is still poorly understood. Analytical models based on the…

Astrophysics of Galaxies · Physics 2010-01-29 Oliver Gressel

Planetary and stellar dynamos likely result from turbulent motions in magnetofluids with kinematic viscosities that are small compared to their magnetic diffusivities. Laboratory experiments are in progress to produce similar dynamos in…

Astrophysics · Physics 2009-11-11 P. D. Mininni

We analyze the initial, kinematic stage of magnetic field evolution in an isotropic and homogeneous turbulent conducting fluid with a rough velocity field, v(l) ~ l^alpha, alpha<1. We propose that in the limit of small magnetic Prandtl…

Astrophysics · Physics 2007-05-23 Stanislav Boldyrev , Fausto Cattaneo

We study the influence of initial conditions on the magnetic field amplification during the collapse of a magnetised gas cloud. We focus on the dependence of the growth and saturation level of the dynamo generated field on the turbulent…

Solar and Stellar Astrophysics · Physics 2015-06-04 Sharanya Sur , Christoph Federrath , Dominik R. G. Schleicher , Robi Banerjee , Ralf S. Klessen

Magnetism is one of the four fundamental forces. However, the origin of magnetic fields in stars, galaxies and clusters is an open problem in astrophysics and fundamental physics. When and how were the first fields generated? Are…

Astrophysics · Physics 2009-11-10 B. M. Gaensler , R. Beck , L. Feretti

In the standard model of cosmic structure formation, dark matter haloes form by gravitational instability. The process is hierarchical: smaller systems collapse earlier, and later merge to form larger haloes. The galaxy clusters, hosted by…

Astrophysics · Physics 2009-11-13 Carlo Giocoli , Lidia Pieri , Giuseppe Tormen

The origin of large-scale magnetic fields, detected in some low-mass (dwarf and irregular) galaxies via polarised synchrotron emission and Faraday rotation, remained unexplained for a long time. We suggest that mean-field dynamo can be…

Astrophysics of Galaxies · Physics 2019-10-16 Prasanta Bera , Anvar Shukurov , Kandaswamy Subramanian

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

Recent theoretical studies have suggested that a magnetic field may play a crucial role in the first star formation in the universe. However, the influence of the magnetic field on the first star formation has yet to be understood well. In…

Astrophysics of Galaxies · Physics 2021-05-26 Kenji Eric Sadanari , Kazuyuki Omukai , Kazuyuki Sugimura , Tomoaki Matsumoto , Kengo Tomida

We consider the evolution of primordial magnetic fields generated during cosmological, electroweak or QCD, phase transitions. We assume that the magnetic field generation can be described as an injection of magnetic energy to cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-24 Tina Kahniashvili , Alexander G. Tevzadze , Axel Brandenburg , Andrii Neronov

The universe is magnetized on all scales probed so far. On the largest scales, galaxies and galaxy clusters host magnetic fields at the micro Gauss level coherent on scales up to ten kpc. Recent observational evidence suggests that even the…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-26 Kandaswamy Subramanian

The properties of the first galaxies are shaped in large part by the first generations of stars, which emit high energy radiation and unleash both large amounts of mechanical energy and the first heavy elements when they explode as…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-15 Jarrett L. Johnson

Magnetic fields pervade the entire Universe and affect the formation and evolution of astrophysical systems from cosmological to planetary scales. The generation and dynamical amplification of extragalactic magnetic fields through cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-27 F. Rincon , F. Califano , A. A. Schekochihin , F. Valentini

We use FIRE-2 cosmological zoom-in hydrodynamic simulations to investigate the co-evolution between Milky Way-size galaxies and their host dark matter halos. We find that the formation of these galaxies follows a two-phase pattern, with an…

Astrophysics of Galaxies · Physics 2026-04-29 Qinglin Ma , Yangyao Chen , Houjun Mo

This paper presents scale invariant/self-similar galactic magnetic dynamo models based on the classic equations, and compares them qualitatively to recently observed magnetic fields in edge-on spiral galaxies. We classify the axially…

Astrophysics of Galaxies · Physics 2021-11-03 R. H. Henriksen , Judith Irwin

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

Magnetohydrodynamic turbulence and magnetic reconnection are ubiquitous in astrophysical environments. In most situations, these processes do not occur in isolation, but interact with each other. This renders a comprehensive theory of these…

Plasma Physics · Physics 2018-03-29 L. Comisso , Y. -M. Huang , M. Lingam , E. Hirvijoki , A. Bhattacharjee

Magnetic fields play a very important role in the evolution of galaxies through their direct impact on star formation and stellar feedback-induced turbulence. However, their co-evolution with these processes has still not been thoroughly…

Astrophysics of Galaxies · Physics 2018-11-14 Evangelia Ntormousi

The true nature of primordial magnetic fields (PMFs) and their role in the formation of galaxies still remains elusive. To shed light on these unknowns, we investigate their impact by varying two sets of properties: (i) accounting for the…

Astrophysics of Galaxies · Physics 2024-10-02 Mahsa Sanati , Sergio Martin-Alvarez , Jennifer Schober , Yves Revaz , Adrianne Slyz , Julien Devriendt