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Related papers: Cosmic-ray driven dynamo in the medium of irregula…

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We investigate numerically the contribution to the cosmic gamma-ray background from cosmic-rays ions and electrons accelerated at intergalactic shocks associated with cosmological structure formation. We show that the kinetic energy of…

Astrophysics · Physics 2008-11-26 Francesco Miniati

To study some characteristics of the interstellar medium, observational data of pulsars with large Faraday rotation values (|RM|> 300 rad / m2) were used. It was suggested and justified that large |RM| values can be due to the contribution…

Astrophysics of Galaxies · Physics 2018-08-13 R. R. Andreasyan , H. R. Andreasyan , G. M. Paronyan

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

Magnetic fields are known to be dynamically important in the interstellar medium of our own Galaxy, and they are ubiquitously observed in diffuse gas in the halos of galaxies and galaxy clusters. Yet, magnetic fields have typically been…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-05 R. Pakmor , V. Springel

Magnetic fields are widely recognised as critical at many scales to galactic dynamics and structure, including multiphase pressure balance, dust processing, and star formation. Using imposed magnetic fields cannot reliably model the…

Astrophysics of Galaxies · Physics 2024-01-17 Frederick A. Gent , Mordecai-Mark Mac Low , Maarit J. Korpi-Lagg

Observational evidence for dynamo action in spiral galaxies is reviewed, and the capabilities of various theories in explaining the basic features of galactic magnetic fields are discussed. Mean-field dynamo models appear to be unique in…

Astrophysics · Physics 2007-05-23 Anvar Shukurov

We study the effects of galaxy formation physics on the magnetization of the intergalactic medium (IGM) using the IllustrisTNG simulations. We demonstrate that large-scale regions affected by the outflows from galaxies and clusters contain…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-30 Andres Aramburo Garcia , Kyrylo Bondarenko , Alexey Boyarsky , Dylan Nelson , Annalisa Pillepich , Anastasia Sokolenko

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

Multi-frequency radio polarimetry of the diffuse Galactic synchrotron background gives new viewpoints on the Galactic magnetic field. Rotation measure maps reveal magnetic structures on arcminute to degree scales, such as a ring in…

Astrophysics · Physics 2015-06-24 M. Haverkorn , P. Katgert , A. G. de Bruyn , F. Heitsch

We explore the impact of diffusive cosmic rays (CRs) on the evolution of the interstellar medium (ISM) under varying assumptions of supernova explosion environment. In practice, we systematically vary the relative fractions of supernovae…

Astrophysics of Galaxies · Physics 2022-12-28 Christine M. Simpson , Rüdiger Pakmor , Christoph Pfrommer , Simon C. O. Glover , Rowan Smith

We propose a model for Diffusive Shock Acceleration (DSA) in which stochastic magnetic fields in the shock precursor are generated through purely fluid mechanisms of a so-called small-scale dynamo. This contrasts with previous DSA models…

High Energy Astrophysical Phenomena · Physics 2015-05-14 A. Beresnyak , T. W. Jones , A. Lazarian

Aims. We investigate the cosmological evolution of large- and small-scale magnetic fields in galaxies in the light of present models of formation and evolution of galaxies. Methods. We use the dynamo theory to derive the timescales of…

Astrophysics · Physics 2009-11-13 Tigran G. Arshakian , Rainer Beck , Marita Krause , Dmitry Sokoloff

Large reservoirs of cold (~ 10^4 K) gas exist out to and beyond the virial radius in the circumgalactic medium (CGM) of all types of galaxies. Photoionization modeling suggests that cold CGM gas has significantly lower densities than…

The Universe at present is highly magnetized, with fields of the order of a few 10^-5 G and coherence lengths larger than 10 kpc in typical galaxies like the Milky Way. We propose that the magnetic field was amplified to this values already…

Astrophysics of Galaxies · Physics 2015-06-17 Jennifer Schober , Dominik R. G. Schleicher , Ralf S. Klessen

We consider the possibility that cosmic magnetic field, instead of being uniformly distributed, is strongly correlated with the large scale structure of the universe. Then, the observed rotational measure of extra-galactic radio sources…

Astrophysics · Physics 2011-07-19 Dongsu Ryu , Hyesung Kang , Peter L. Biermann

Radio synchrotron emission is a powerful tool to study the strength and structure of magnetic fields in galaxies. Unpolarized synchrotron emission traces isotropic turbulent fields which are strongest in spiral arms and bars (20-30 \mu G)…

Astrophysics of Galaxies · Physics 2016-01-11 Rainer Beck

How cosmic rays sample the multi-phase interstellar medium (ISM) in starburst galaxies has important implications for many science goals, including evaluating the cosmic ray calorimeter model for these systems, predicting their neutrino…

High Energy Astrophysical Phenomena · Physics 2013-11-22 Erin Boettcher , Ellen G. Zweibel , Tova M. Yoast-Hull , J. S. Gallagher

Interstellar magnetic fields in elliptical galaxies are assumed to have their origin in stellar fields that accompany normal mass loss from an evolving population of old stars. The seed fields are amplified by interstellar turbulence driven…

Astrophysics · Physics 2009-10-30 William G. Mathews , Fabrizio Brighenti

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

Magnetic field amplification by a fast dynamo is seen in local box simulations of SN-driven ISM turbulence, where the self-consistent emergence of large-scale fields agrees very well with its mean-field description. We accordingly derive…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-25 Detlef Elstner , Oliver Gressel