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Related papers: Cosmic-ray driven dynamo in galactic disks

200 papers

Cosmic rays (CRs) and magnetic fields may be dynamically important in driving large-scale galactic outflows from rapidly star-forming galaxies. We construct two-dimensional axisymmetric models of the local starburst and super-wind galaxy…

Astrophysics of Galaxies · Physics 2020-04-29 Benjamin J. Buckman , Tim Linden , Todd A. Thompson

We examine the effects of streaming cosmic rays upstream of a strong, parallel collisionless shock. We include explicitly the inertia of the cosmic rays in our analysis, which was neglected in previous work. For parameters relevant to the…

High Energy Astrophysical Phenomena · Physics 2012-06-20 E. J. Greenfield , J. R. Jokipii , J. Giacalone

Current-day cosmic ray (CR) propagation studies use static Milky-Way models and fit parametrized source distributions to data. Instead, we use three-dimensional magneto-hydrodynamical (MHD) simulations of isolated galaxies with the…

High Energy Astrophysical Phenomena · Physics 2021-05-25 Maria Werhahn , Christoph Pfrommer , Philipp Girichidis , Ewald Puchwein , Rüdiger Pakmor

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

We investigate the appearance of magnetic field amplification resulting from a cosmic ray escape current in the context of supernova remnant shock waves. The current is inversely proportional to the maximum energy of cosmic rays, and is a…

High Energy Astrophysical Phenomena · Physics 2015-06-16 K. M. Schure , A. R. Bell

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…

Diffusive shock acceleration operating at expanding supernova remnant shells is by far the most popular model for the origin of galactic cosmic rays. Despite the general consensus received by this model, an unambiguous and conclusive proof…

Astrophysics · Physics 2008-11-07 Stefano Gabici

Galactic cosmic rays are believed to be accelerated at supernova remnant shocks. Though very popular and robust, this conjecture still needs a conclusive proof. The strongest support to this idea is probably the fact that supernova remnants…

High Energy Astrophysical Phenomena · Physics 2015-06-15 P. Cristofari , S. Gabici , S. Casanova , R. Terrier , E. Parizot

Galactic cosmic rays are believed to be mostly accelerated at supernova shocks. However, the interstellar magnetic field is too weak to efficiently accelerate galactic cosmic rays up to the highest energies, i.e. $10^{15}$ eV. A stronger…

High Energy Astrophysical Phenomena · Physics 2016-03-16 Maria Victoria del Valle , Alexandre Lazarian , Reinaldo Santos-Lima

This is the second paper (the first was astro-ph/9704267) of a series analysing the Galactic Cosmic Ray (GCR) composition and origin. In this we present a quantitative model of GCR origin and acceleration based on the acceleration of a…

Astrophysics · Physics 2009-10-30 Donald C. Ellison , L. O'C. Drury , Jean-Paul Meyer

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

Evidence for wave-like corrugations are well established in the Milky Way and in nearby disc galaxies. These were originally detected as a displacement of the interstellar medium about the midplane, either in terms of vertical distance or…

Astrophysics of Galaxies · Physics 2022-07-28 Thor Tepper-Garcia , Joss Bland-Hawthorn , Ken Freeman

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 pervade the entire Universe and affect the formation and evolution of astrophysical systems from cosmological to planetary scales. The generation and dynamical amplification of extragalactic magnetic fields through cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-27 F. Rincon , F. Califano , A. A. Schekochihin , F. Valentini

We examine the question of the origin of the Galactic cosmic-rays (GCRs) in the light of the data available at the highest energy end of the spectrum. We argue that the data of the Pierre Auger Observatory and of the KASCADE-Grande…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Etienne Parizot

We study the formation of galactic outflows from supernova explosions (SNe) with the moving-mesh code AREPO in a stratified column of gas with a surface density similar to the Milky Way disk at the solar circle. We compare different…

Possible formulations of the problem of cosmic rays acceleration in the interstellar galactic medium are considered with the use of fractional differential equations. The applied technique has been physically justified. A Fermi result has…

Astrophysics of Galaxies · Physics 2011-05-19 V. V. Uchaikin

Many galaxies contain magnetic fields supported by galactic dynamo action. However, nothing definitive is known about magnetic fields in ring galaxies. Here we investigate large-scale magnetic fields in a previously unexplored context,…

Astrophysics of Galaxies · Physics 2016-07-20 D. Moss , E. Mikhailov , O. Silchenko , D. Sokoloff , C. Horellou , R. Beck

We show that a purely kinetic approach to the excitation of waves by cosmic rays in the vicinity of a shock front leads to predict the appearance of a non-alfv\'enic fastly growing mode which has the same dispersion relation as that…

Astrophysics · Physics 2009-11-13 Elena Amato , Pasquale Blasi

A review of galactic magnetic fields is given with emphasis on simple analytical solutions of relevant equations and detailed comparison with observations. It is shown that mean-field dynamo theory, in its simplest form, is in a remarkably…

Astrophysics · Physics 2007-05-23 Anvar Shukurov