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Related papers: Magnetic field reversals and galactic dynamos

200 papers

Neutron stars, and magnetars in particular, are known to host the strongest magnetic fields in the Universe. The origin of these strong fields is a matter of controversy. In this preliminary work, via numerical simulations, we study, for…

High Energy Astrophysical Phenomena · Physics 2020-06-30 K. Franceschetti , L. Del Zanna

The origin of the magnetic field in galaxies is an open question in astrophysics. Several mechanisms have been proposed related, in general, with the generation of small seed fields amplified by a dynamo mechanism. In general, these…

Astrophysics · Physics 2009-10-30 O. D. Miranda , M. Opher , R. Opher

Magnetic fields play an important role at all stages of stellar evolution. In Sun-like stars, they are generated in the outer convective layers. Studying the large-scale magnetic fields of these stars enlightens our understanding of the…

Solar and Stellar Astrophysics · Physics 2015-06-17 R. Fares

Interstellar magnetic fields are strong: up to 25 muG in spiral arms and 40 muG in nuclear regions. In the spiral galaxy NGC 6946 the average magnetic energy density exceeds that of the thermal gas. Magnetic fields control the evolution of…

Astrophysics · Physics 2017-01-25 Rainer Beck

Observations of sun-like stars rotating faster than our current sun tend to exhibit increased magnetic activity as well as magnetic cycles spanning multiple years. Using global simulations in spherical shells to study the coupling of…

Solar and Stellar Astrophysics · Physics 2015-05-20 Nicholas J. Nelson , Benjamin P. Brown , Matthew K. Browning , Allan Sacha Brun , Mark S. Miesch , Juri Toomre

I review the large scale global magnetic field structure of our Galaxy, using all information available for disk fields, halo fields and magnetic fields near the Galactic center (GC). In the local disk of our Galaxy, RM and dispersion…

Astrophysics · Physics 2015-06-11 Jinlin Han

It is argued that large scale cosmic magnetic field could be generated in the primeval plasma slightly before hydrogen recombination. Non-zero vorticity, necessary for that, might be created by the photon diffusion in the second order in…

Astrophysics · Physics 2016-08-30 Z. Berezhiani , A. D. Dolgov

We generalize the mean field magnetic dynamo to include local evolution of the mean vorticity in addition to the mean magnetic field. The coupled equations exhibit a general mean field dynamo instability that enables the transfer of…

Astrophysics · Physics 2009-10-30 Eric G. Blackman , Tom Chou

We develop an analytical model to follow the cosmological evolution of magnetic fields in disk galaxies. Our assumption is that fields are amplified from a small seed field via magnetohydrodynamical (MHD) turbulence. We further assume that…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Stanislav Shabala , James M. G. Mead , Paul Alexander

Turbulence is believed to play important roles in the origin of cosmic magnetism. While it is well known that turbulence can efficiently amplify a uniform or spatially homogeneous seed magnetic field, it is not clear whether or not we can…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Jungyeon Cho

Magnetic fields have been detected on stars across the H-R diagram and substellar objects either directly by their effect on the formation of spectral lines, or through the activity phenomena they power which can be observed across a large…

Solar and Stellar Astrophysics · Physics 2015-06-11 J. Morin

Enormous progress has been made on observing stellar magnetism in stars from the main sequence through to compact objects. Recent data have thrown into sharper relief the vexed question of the origin of stellar magnetic fields, which…

Solar and Stellar Astrophysics · Physics 2015-06-24 Lilia Ferrario , Andrew Melatos , Jonathan Zrake

In this review, I will first introduce possible methods to probe the large-scale magnetic fields in our Galaxy and discuss their limitations. The magnetic fields in the Galactic halo, mainly revealed by the sky distribution of rotation…

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

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

We bring the two color maps for the plane component magnetic field of our Galaxy in coordinates of (R;l) and (DM;l). It was shown that magnetic field has reversals of the direction in neighbor spiral arms, in agreement with known models for…

Astrophysics of Galaxies · Physics 2010-12-06 R. Andreasyan , S. Balayan , V. Movsisyan

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

The origin and sustenance of large scale galactic magnetic fields has been a long standing and controversial astrophysical problem. Here an alternative to the ``standard'' $\a-\Omega$ mean field dynamo and primordial theories is pursued.…

Astrophysics · Physics 2009-10-30 Eric G. Blackman

Rotation has a number of important effects on the evolution of stars. It decreases the surface gravity, causes enhanced mass loss and leads to surface abundance anomalies of various chemical isotopes. We have adapted the Cambridge stellar…

Solar and Stellar Astrophysics · Physics 2012-05-31 Adrian T. Potter

Most of the baryonic matter in the Universe is permeated by magnetic fields which affect many, if not most, of astrophysical phenomena both, in compact sources and in diffuse gas. Recent years have been marked by a worldwide surge of…

Cosmology and Nongalactic Astrophysics · Physics 2010-03-23 Elisabete M. de Gouveia Dal Pino

The evolution of large-scale magnetic fields in disk galaxies is investigated numerically. The gasdynamical simulations in a disk perturbed by spiral or bar potential are incorporated into the kinematic calculations of induction equations…

Astrophysics · Physics 2007-05-23 K. Otmianowska-Mazur , M. Chiba
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