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We study the cosmic evolution of the magnetic fields of a large sample of spiral galaxies in a cosmologically representative volume by employing a semi-analytic galaxy formation model and numerical dynamo solver in tandem. We start by…

Astrophysics of Galaxies · Physics 2019-01-03 Luiz Felippe S. Rodrigues , Luke Chamandy , Anvar Shukurov , Carlton M. Baugh , A. Russ Taylor

Galactic magnetic arms have been observed between the gaseous arms of some spiral galaxies; their origin remains unclear. We suggest that magnetic spiral arms can be naturally generated in the interarm regions because the galactic fountain…

Astrophysics of Galaxies · Physics 2015-06-22 Luke Chamandy , Anvar Shukurov , Kandaswamy Subramanian

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

Hydrostatic equilibrium of the multiphase interstellar medium in the solar vicinity is reconsidered, with the regular and turbulent magnetic fields treated separately. The regular magnetic field strength required to support the gas is…

Astrophysics · Physics 2009-11-06 Andrew Fletcher , Anvar Shukurov

In models for gamma ray burst afterglows, it is normally assumed that the external shock strongly amplifies the magnetic field and that this field maintains a steady value throughout the shocked region. We discuss the effects of modifying…

Astrophysics · Physics 2009-11-07 Elena Rossi , Martin J. Rees

Binary neutron-star mergers have long been associated with short-duration gamma-ray bursts (GRBs). This connection was confirmed with the first coincident detection of gravitational waves together with electromagnetic radiation from…

High Energy Astrophysical Phenomena · Physics 2019-10-11 Antonios Nathanail , Oliver Porth , Luciano Rezzolla

In this work we numerically calculate the thermal radiation efficiency of the baryonic outflow. The possible outflow acceleration in the transparent stage, which lowers thermal radiation efficiency, has been taken into account. In the…

Cosmology and Nongalactic Astrophysics · Physics 2011-04-07 Yi-Zhong Fan

It is shown that the standard cosmological model predicts {\it ab initio} generation of large-scale but very small-amplitude cosmic magnetic fields at the epoch of recombination of the primeval plasma. Matter velocities dominated by…

Astrophysics · Physics 2007-05-23 Craig J. Hogan

There is mounting evidence that the ejection of magnetic helicity from the solar surface is important for the solar dynamo. Observations suggest that in the northern hemisphere the magnetic helicity flux is negative. We propose that this…

Astrophysics · Physics 2009-11-07 A. Brandenburg , E. G. Blackman , G. R. Sarson

Magnetic buoyancy (MBI) and Parker instabilities are strong, generic instabilities expected to occur in most astrophysical systems with sufficiently strong magnetic fields. In galactic and accretion discs, large-scale magnetic fields are…

Astrophysics of Galaxies · Physics 2025-04-11 Yasin Qazi , Anvar. Shukurov , Frederick. A. Gent , Devika. Tharakkal , Abhijit. B. Bendre

The joint analysis of the Dispersion and Faraday Rotation Measure from distant, polarised Fast Radio Bursts may be used to put constraints on the origin and distribution of extragalactic magnetic fields on cosmological scales. While the…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-24 F. Vazza , M. Brüggen , P. M. Hinz , D. Wittor , N. Locatelli , C. Gheller

The rate of terrestrial irradiation events by galactic gamma-ray bursts (GRBs) is estimated using recent standard-energy results. We assume that GRBs accelerate high-energy cosmic rays, and present results of three-dimensional simulations…

Astrophysics · Physics 2009-11-10 Charles D. Dermer , Jeremy M. Holmes

The source of cosmic gamma-ray bursts (hereafter GRBs) is usually believed to be a stellar mass black hole accreting material from a thick disk. The mechanism for the production of a relativistic wind by such a system is still unknown. We…

Astrophysics · Physics 2009-10-31 Frederic Daigne , Robert Mochkovitch

Persistent activity of magnetars is associated with electric discharge that continually injects relativistic particles into the magnetosphere. Large active magnetic loops around magnetars must be filled with outflowing particles that…

High Energy Astrophysical Phenomena · Physics 2015-06-03 Andrei M. Beloborodov

A recent article from the Pierre Auger Collaboration links the direction of charged cosmic rays to possible extragalactic sites of emission. The correlation of the direction of such particles with the direction of the emitter allows…

Astrophysics · Physics 2008-11-26 Alessandro De Angelis , Massimo Persic , Marco Roncadelli

This paper shows that magnetic reconnection could be an important heating process in cosmic gases. In any volume where magnetized plasmas collide, the dissipation of magnetic energy via reconnection seems to be unavoidable. Since most…

Astrophysics · Physics 2007-05-23 F. Zimmer , H. Lesch , G. T. Birk

Magnetic fields play a central role in accretion physics around black holes, yet their physical origin within accretion flows remains an open problem. In this work, we investigate the generation and subsequent evolution of magnetic fields…

High Energy Astrophysical Phenomena · Physics 2026-02-03 Mukesh Kumar Vyas , Asaf Pe'er

We study the emergence of magnetic flux from the near-surface layers of the solar convection zone into the photosphere. To model magnetic flux emergence, we carried out a set of numerical radiative magnetohydrodynamics simulations. Our…

Astrophysics · Physics 2009-11-13 Mark Chun Ming Cheung , Manfred Schuessler , Fernando Moreno-Insertis

We study dissipation process of magnetic fields in the metallicity range $0-1 Z_{\odot}$ for contracting prestellar cloud cores. By solving non-equilibrium chemistry for important charged species including charged grains, we evaluate the…

Solar and Stellar Astrophysics · Physics 2015-06-23 Hajime Susa , Kentaro Doi , Kazuyuki Omukai

We aim to estimate the contribution of the radial component of the Lorentz force to the gas rotation in several types of galaxies. Using typical parameters for the exponential scale of synchrotron emission and the scale length of HI gas,…

Astrophysics of Galaxies · Physics 2014-09-05 Detlef Elstner , Rainer Beck , Oliver Gressel