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Related papers: Cosmic-ray driven dynamo in galaxies

200 papers

We investigate the effects of cosmic ray (CR) dynamics on cold, dense clouds embedded in a hot, tenuous galactic halo. If the magnetic field does not increase too much inside the cloud, the local reduction in Alfv\'en speed imposes a…

High Energy Astrophysical Phenomena · Physics 2017-01-25 Joshua Wiener , S. Peng Oh , Ellen G. Zweibel

Cosmic rays (CRs) are a non-thermal energy component in the interstellar and circumgalactic medium (CGM) that can act as an additional feedback channel beyond thermal and kinetic feedback from stars and AGN. They influence galaxy evolution…

The recent observations revealed that the cosmic-ray (CR) proton spectrum showed a complex structure: the hardening at $\rm \sim 200~GeV$ and softening at $\rm \sim 10~TeV$. However, so far the physical origins of this spectral feature…

High Energy Astrophysical Phenomena · Physics 2023-07-26 Lin Nie , Yang Liu , Zejun Jiang

Latest precise cosmic-ray (CR) measurements and present gamma-ray observations have started challenging our understanding of CR transport and interaction in the Galaxy. Moreover, because the density of CRs is similar to the density of the…

We have calculated the evolution of cosmic ray (CR) modified astrophysical shocks for a wide range of shock Mach numbers and shock speeds through numerical simulations of diffusive shock acceleration (DSA) in 1D quasi- parallel plane…

Astrophysics · Physics 2009-11-10 H. Kang , T. W. Jones

Non-thermal (relativistic) particles are injected into the cosmos by structure formation shock waves, active galactic nuclei and stellar explosions. We present a suite of unigrid cosmological simulations (up to $2048^3$) using a two-fluid…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-05 Franco Vazza , Claudio Gheller , Marcus Brüggen

We investigate the impact of cosmic rays (CRs) on the circumgalactic medium (CGM) in FIRE-2 simulations, for ultra-faint dwarf through Milky Way (MW)-mass halos hosting star-forming (SF) galaxies. Our CR treatment includes injection by…

We study the generation and maintenance of large-scale magnetic fields in barred galaxies. We take a velocity field (with strong noncircular components) from a published gas dynamical simulation of Athanassoula (1992), and use this as input…

Astrophysics · Physics 2009-11-06 D. Moss , A. Shukurov , D. Sokoloff , R. Beck , A. Fletcher

We argue that clusters of galaxies have an intergalactic medium, which is permeated by strong magnetic fields and also has a contribution of pressure from cosmic rays. These two components of total pressure are probably highly time…

Astrophysics · Physics 2016-08-16 Peter L. Biermann , Torsten A. Enßlin , Hyesung Kang , Hyesook Lee , Dongsu Ryu

Core collapse supernovae (CCSNe) produce fast shocks which pervade the dense circum-stellar medium (CSM) of the stellar progenitor. Cosmic rays (CRs) if accelerated at these shocks can induce the growth of electromagnetic fluctuations in…

High Energy Astrophysical Phenomena · Physics 2018-07-18 Alexandre Marcowith , Vikram Dwarkadas , Matthieu Renaud , Vincent Tatischeff , Gwenael Giacinti

Supernova remnants (SNRs) are believed to be the source of Galactic cosmic rays (CRs). SNR shocks accelerate CR protons and electrons which reveal key insights into the non-thermal physics by means of their synchrotron and $\gamma$-ray…

High Energy Astrophysical Phenomena · Physics 2020-12-08 Georg Winner , Christoph Pfrommer , Philipp Girichidis , Maria Werhahn , Matteo Pais

Cosmic rays (CRs) are thought to play an important role in galaxy evolution. We study their effect when coupled to other important sources of feedback, namely supernovae and stellar radiation, by including CR anisotropic diffusion and…

Astrophysics of Galaxies · Physics 2022-05-27 Marion Farcy , Joakim Rosdahl , Yohan Dubois , Jérémy Blaizot , Sergio Martin-Alvarez

The properties of the Galactic supernova remnant SN 1006 are theoretically reanalysed. Nonlinear kinetic theory is used to determine the acceleration efficiency of cosmic rays (CRs) in the supernova remnant SN 1006. The known range of…

High Energy Astrophysical Phenomena · Physics 2011-03-22 E. G. Berezhko , L. T. Ksenofontov , H. J. Voelk

Supernovae are the dominant energy source for driving turbulence within the interstellar plasma. Until recently, their effects on magnetic field amplification in disk galaxies remained a matter of speculation. By means of self-consistent…

Astrophysics · Physics 2009-11-13 Oliver Gressel , Udo Ziegler , Detlef Elstner , Günther Rüdiger

Diffusion of cosmic rays (CRs) is the key process of understanding their propagation and acceleration. We employ the description of spatial separation of magnetic field lines in MHD turbulence in Lazarian & Vishniac (1999) to quantify the…

High Energy Astrophysical Phenomena · Physics 2016-12-21 A. Lazarian , Huirong Yan

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

A model is introduced, in which the irregularity spectrum of the Galactic magnetic field beyond the dissipation length scale is first a Kolmogorov spectrum $k^{-5/3}$ at small scales $\lambda \, = \, 2 \pi/k$ with $k$ the wave-number, then…

High Energy Astrophysical Phenomena · Physics 2015-11-16 P. L. Biermann , L. I. Caramete , A. Meli , B. N. Nath , E. -S. Seo , V. de Souza , J. Becker Tjus

We perform kinetic simulations of diffusive shock acceleration (DSA) in Type Ia supernova remnants (SNRs) expanding into a uniform interstellar medium (ISM). Bohm-like diffusion assumed, and simple models for Alfvenic drift and dissipation…

High Energy Astrophysical Phenomena · Physics 2017-01-18 Hyesung Kang

Cosmic ray acceleration by shocks related with Slipping Interaction Regions (SIRs) in the Galactic Wind is considered. SIRs are similar to Solar Wind Corotating Interaction Regions. The spiral structure of our Galaxy results in a strong…

Astrophysics · Physics 2009-11-10 H. J. Voelk , V. N. Zirakashvili

Galactic cosmic rays (CRs) are a fundamental non-thermal component of the interstellar medium (ISM). Understanding the transport of super-high-energy particles is essential for interpreting observations of Galactic PeVatrons. Classical…

High Energy Astrophysical Phenomena · Physics 2026-04-07 Yue Hu