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Using cosmological MHD simulations of the magnetic field in galaxy clusters and filaments we evaluate the possibility to infer the magnetic field strength in filaments by measuring cross-correlation functions between Faraday Rotation…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 F. Stasyszyn , S. E. Nuza , K. Dolag , R. Beck , J. Donnert

The density profiles of dark halos are usually inferred from the rotation curves of disk galaxies based on the assumption that the gas is a good tracer of the gravitational potential of the galaxies. Some authors have suggested that…

Astrophysics · Physics 2009-11-10 F. J. Sanchez-Salcedo , M. Reyes-Ruiz

Magnetic fields appear everywhere in the universe. From stars and galaxies, all the way to galaxy clusters and remote protogalactic clouds magnetic fields of considerable strength and size have been repeatedly observed. Despite their…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Alejandra Kandus , Kerstin E. Kunze , Christos G. Tsagas

We perform three-dimensional numerical simulations of stellar winds of early-M dwarf stars. Our simulations incorporate observationally reconstructed large-scale surface magnetic maps, suggesting that the complexity of the magnetic field…

Solar and Stellar Astrophysics · Physics 2015-06-18 A. A. Vidotto , M. Jardine , J. Morin , J. F. Donati , M. Opher , T. I. Gombosi

Direct numerical simulations of turbulent Hall dynamos are presented. The evolution of an initially weak and small scale magnetic field in a system maintained in a stationary turbulent regime by a stirring force at a macroscopic scale is…

Astrophysics · Physics 2009-11-10 P. D. Mininni , D. O. Gómez , S. M. Mahajan

Convectively driven dynamos with rotation generating magnetic fields on scales large compared with the scale of the turbulent eddies are being reviewed. It is argued that such fields can be understood as the result of an alpha effect.…

Solar and Stellar Astrophysics · Physics 2011-08-19 A. Brandenburg , P. J. Käpylä , M. J. Korpi

The prevailing theory for the origin of cosmic magnetic fields is that they have been amplified to their present values by the turbulent dynamo inductive action in the protogalactic and galactic medium. Up to now, in calculation of the…

Astrophysics · Physics 2007-05-23 Leonid Malyshkin

Magnetic fields are an important component of the interstellar medium (ISM) of galaxies. The thermal gas in the ISM has a multiphase structure, broadly divided into ionised, atomic, and molecular phases. The connection between the…

Astrophysics of Galaxies · Physics 2025-04-01 Amit Seta , N. M. McClure-Griffiths

This chapter presents a review of observational studies to determine the magnetic field in the Milky Way, both in the disk and in the halo, focused on recent developments and on magnetic fields in the diffuse interstellar medium. I discuss…

Astrophysics of Galaxies · Physics 2015-06-19 Marijke Haverkorn

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 physics of magnetic fields ($\textbf{B}$) and cosmic rays (CRs) have recently been included in simulations of galaxy formation. However, significant uncertainties remain in how these components affect galaxy evolution. To understand…

There is evidence that cosmic rays were present in galaxies at moderately high redshift. This suggests that magnetic fields were also present. If cosmic rays and magnetic fields must always be close to equipartition, as they are to an order…

Astrophysics · Physics 2009-11-07 Ellen G. Zweibel

We conduct simulations of $\sim$kpc-scale cool clouds in the circumgalactic medium (CGM), using initial conditions sampled from a highly resolved cosmological magneto-hydrodynamical zoom-in of a Milky Way-like galaxy. We select ten distinct…

Astrophysics of Galaxies · Physics 2026-03-02 Rahul Ramesh , Dylan Nelson , Drummond Fielding , Marcus Brüggen

A decade ago, there was very limited knowledge of magnetic fields of our Galaxy. The local fields in the Solar vicinity were known to be directed towards a Galactic longitude $l\sim~90^{\circ}$ with reversed directions at smaller…

Astrophysics · Physics 2007-05-23 J. L. Han

Low-mass galaxies radio observations show in many cases surprisingly high levels of magnetic field. The mass and kinematics of such objects do not favour the development of effective large-scale dynamo action. We attempted to check if the…

Astrophysics of Galaxies · Physics 2018-03-14 Hubert Siejkowski , Marian Soida , Krzysztof T. Chyzy

Magnetic fields are one of most concealed components of the universe. They are observed as part of the intergalactic medium and on galaxy cluster scales, however their origin and evolution is unclear. In this work we use the IllustrisTNG…

Astrophysics of Galaxies · Physics 2023-05-04 Agustín M. Rodríguez-Medrano , Federico A. Stasyszyn , Dante J. Paz , Volker Springel

We present a scenario for efficient magnetization of very young galaxies about 0.5 Gigayears after the Big-Bang by a cosmic ray-driven dynamo. These objects experience a phase of strong star formation during this first $10^9$ years. We…

Astrophysics · Physics 2009-11-07 H. Lesch , M. Hanasz

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

Magnetic fields are ubiquitous in the Universe. Recently, cosmological simulations of galaxies have successfully begun to incorporate magnetic fields and their evolution in galaxies and their haloes. However, so far they have mostly focused…

Here we summarize our recent results of high-resolution computer simulations on the turbulent amplification of weak magnetic seed fields showing that such fields will be exponentially amplified also during the gravitational collapse…

Cosmology and Nongalactic Astrophysics · Physics 2012-02-22 Robi Banerjee , Sharanya Sur , Christoph Federrath , Dominik R. G. Schleicher , Ralf S. Klessen