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We present results of three-dimensional nonlinear MHD simulations of a large-scale magnetic field and its evolution inside a barred galaxy with the back reaction of the magnetic field on the gas. The model does not consider the dynamo…

Astrophysics of Galaxies · Physics 2015-05-13 B. Kulesza-Zydzik , K. Kulpa-Dybel , K. Otmianowska-Mazur , G. Kowal , M. Soida

We investigate the dynamics of magnetic fields in spiral galaxies by performing 3D MHD simulations of galactic discs subject to a spiral potential. Recent hydrodynamic simulations have demonstrated the formation of inter-arm spurs as well…

Astrophysics · Physics 2009-11-13 C. L. Dobbs , D. J. Price

The magnetic field of galaxies is believed to be produced by internal dynamo action, but can be affected by motion of the galaxy through the surrounding medium. Observations of polarized radio emission of galaxies located in galaxy clusters…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 D. Moss , D. Sokoloff , R. Beck

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

Recent progress in observational studies of magnetic activity in M dwarfs urgently requires support from ideas of stellar dynamo theory. We propose a strategy to connect observational and theoretical studies. In particular, we suggest four…

Solar and Stellar Astrophysics · Physics 2015-06-24 D. Shulyak , D. Sokoloff , L. Kitchatinov , D. Moss

(Abridged) Based on the rapidly increasing all-sky data of Faraday rotation measures and polarised synchrotron radiation, the Milky Way's magnetic field is now modelled with an unprecedented level of detail and complexity. We aim to…

Astrophysics of Galaxies · Physics 2015-06-17 Oliver Gressel , Detlef Elstner , Udo Ziegler

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

The origin and structure of the magnetic fields in the interstellar medium of spiral galaxies is investigated with 3D, non-ideal, compressible MHD simulations, including stratification in the galactic gravity field, differential rotation…

Astrophysics of Galaxies · Physics 2013-04-01 F. A. Gent , A. Shukurov , A. Fletcher , G. R. Sarson , M. J. Mantere

Large scale strong magnetic fields in galaxies are generally thought to have been generated by a mean field dynamo. In order to have generated the fields observed, the dynamo would have had to have operated for a sufficiently long period of…

Astrophysics · Physics 2007-05-23 A. Kandus , R. Opher , S. R. M. Barros

Spiral arms are the defining features of broad morphological classes of disc galaxies, but their nature and influence on galaxy evolution is still under debate. A key diagnostic for their nature is the spiral arm pattern speed: the radial…

Instrumentation and Methods for Astrophysics · Physics 2025-12-22 Robert J. J. Grand , Martin Roth

We review the literature concerning how the cosmic magnetic fields pervading nearly all galaxies actually got started. some observational evidence involves the chemical abundance of the light elements Be and B, while another one is based on…

Astrophysics · Physics 2009-11-13 Russell M. Kulsrud , Ellen G. Zweibel

We study how well the complex gas velocity fields induced by massive spiral arms are modelled by the hydrodynamical simulations we used to constrain the dark matter fraction in nearby spiral galaxies (Kranz et al. 2001, 2003). More…

Astrophysics · Physics 2009-11-10 Adrianne Slyz , Thilo Kranz , Hans-Walter Rix

A combination of observation, theory, modeling, and laboratory plasma experiments provides a multifaceted approach to develop a much greater understanding of how magnetic fields arise in galactic settings and how these magnetic fields…

Astrophysics of Galaxies · Physics 2009-02-23 A. Lazarian , S. Boldyrev , C. Forest , J. Sarff , P. Terry

We generated synthetic observations from the four-arm model presented in Gomez & Cox (2004) for the Galactic ISM in the presence of a spiral gravitational perturbation. We found that velocity crowding and diffusion have a strong effect in…

Astrophysics · Physics 2009-11-10 Gilberto C. Gomez , Donald P. Cox

Pitch angles $p$ of the large-scale magnetic fields $\overline{\bf{\it{B}}}$ of spiral galaxies have previously been inferred from observations to be systematically larger in magnitude than predicted by standard mean-field dynamo theory.…

Astrophysics of Galaxies · Physics 2015-08-06 Luke Chamandy , A. Russ Taylor

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 have been observed on all scales in our Galaxy, from AU to kpc. With pulsar dispersion measures and rotation measures, we can directly measure the magnetic fields in a very large region of the Galactic disk. The results show…

Astrophysics · Physics 2009-01-01 Jinlin Han

We investigate the build-up of the galactic dynamo and subsequently the origin of a magnetic driven outflow. We use a setup of an isolated disc galaxy with a realistic circum-galactic medium (CGM). We find good agreement of the galactic…

Astrophysics of Galaxies · Physics 2020-04-01 Ulrich P. Steinwandel , Klaus Dolag , Harald Lesch , Benjamin P. Moster , Andreas Burkert , Almudena Prieto

Results from simulations of hierarchical structure formation cosmology provide a tool to develop an evolutionary model of regular magnetic fields coupled to galaxy formation and evolution. We use the dynamo theory to derive the timescales…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-17 Tigran G. Arshakian , Rainer Beck , Marita Krause , Dmitry Sokolff , Rodion Stepanov

Magnetic fields of laboratory, planetary, stellar, and galactic plasmas commonly exhibit significant order on large temporal or spatial scales compared to the otherwise random motions within the hosting system. Such ordered fields can be…

Solar and Stellar Astrophysics · Physics 2015-06-18 Eric G. Blackman