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Related papers: A new cosmic ray-driven instability

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Cosmic rays (CRs) leave their sources mainly along the local magnetic field; in doing so they excite both resonant and nonresonant modes through streaming instabilities. The excitation of these modes leads to enhanced scattering and in turn…

High Energy Astrophysical Phenomena · Physics 2021-06-10 Benedikt Schroer , Oreste Pezzi , Damiano Caprioli , Colby Haggerty , Pasquale Blasi

The nonresonant cosmic ray instability, predicted by Bell (2004), is thought to play an important role in the acceleration and confinement of cosmic rays (CRs) close to supernova remnants. Despite its importance, the exact mechanism…

High Energy Astrophysical Phenomena · Physics 2019-09-17 Georgios Zacharegkas , Damiano Caprioli , Colby Haggerty

Recent advances on gamma-ray observations from SuperNova Remnants and Molecular Clouds offer the possibility to study in detail the properties of the propagation of escaping Cosmic Rays (CR). However, a complete theory for CR transport…

High Energy Astrophysical Phenomena · Physics 2015-09-09 Lara Nava , Stefano Gabici , Alexandre Marcowith , Giovanni Morlino , Vladimir Ptuskin

We investigate how cosmic rays (CRs) affect thermal and hydrostatic stability of circumgalactic (CGM) gas, in simulations with both CR streaming and diffusion. Local thermal instability can be suppressed by CR-driven entropy mode…

Astrophysics of Galaxies · Physics 2023-05-25 Tsun Hin Navin Tsung , S. Peng Oh , Chad Bustard

Cosmic ray (CR) transport and acceleration is essential for many astrophysical problems, e.g., CMB foreground, ionization of molecular clouds and all high energy phenomena. Recent advances in MHD turbulence call for revisions in the…

High Energy Astrophysical Phenomena · Physics 2011-12-06 Huirong Yan , A. Lazarian

We investigate the growth of hydromagnetic waves driven by streaming cosmic rays in the precursor environment of a supernova remnant shock. It is known that transverse waves propagating parallel to the mean magnetic field are unstable to…

Astrophysics · Physics 2009-11-13 B. Reville , J. G. Kirk , P. Duffy , S. O. Sullivan

Cosmic rays (CRs) are thought to play a dynamically important role in several key aspects of galaxy evolution, including the structure of the interstellar medium, the formation of galactic winds, and the non-thermal pressure support of…

Astrophysics of Galaxies · Physics 2019-11-19 Yohan Dubois , Benoît Commerçon , Alexandre Marcowith , Loann Brahimi

Cosmic rays (CRs) are dynamically important for the formation and evolution of galaxies by regulating star formation and by powering galactic outflows. However, to what extent CRs regulate galaxy formation depends on the coupling strength…

Astrophysics of Galaxies · Physics 2023-12-27 Philipp Girichidis , Maria Werhahn , Christoph Pfrommer , Rüdiger Pakmor , Volker Springel

Using hybrid simulations (kinetic ions--fluid electrons), we test the linear theory predictions of the cosmic ray (CR) streaming instability. We consider two types of CR distribution functions: a "hot" distribution where CRs are represented…

High Energy Astrophysical Phenomena · Physics 2019-09-16 Colby Haggerty , Damiano Caprioli , Ellen Zweibel

The transport of cosmic rays (CRs) is crucial for the understanding of almost all high-energy phenomena. Both pre-existing large-scale magnetohydrodynamic (MHD) turbulence and locally generated turbulence through plasma instabilities are…

High Energy Astrophysical Phenomena · Physics 2018-02-28 Olga Lebiga , Reinaldo Santos-Lima , Huirong Yan

The Parker instability, a Rayleigh-Taylor like instability of thermal gas supported against gravity by magnetic fields and cosmic rays, is thought to be dynamically important for galaxy evolution, possibly promoting molecular cloud…

Astrophysics of Galaxies · Physics 2020-03-25 Evan Heintz , Chad Bustard , Ellen Zweibel

Cosmic ray (CR) currents through magnetised plasma drive strong instabilities producing amplification of the magnetic field. This amplification helps explain the CR energy spectrum as well as observations of supernova remnants and radio…

High Energy Astrophysical Phenomena · Physics 2017-07-31 James H. Matthews , Anthony R. Bell , Katherine M. Blundell , Anabella T. Araudo

Cosmic rays (CRs) streaming in weakly magnetized plasmas can drive large-amplitude magnetic fluctuations via nonresonant streaming instability (NRSI), or Bell instability. Using one-dimensional kinetic simulations, we investigate how…

High Energy Astrophysical Phenomena · Physics 2025-11-27 Saikat Das , Siddhartha Gupta , Prateek Sharma

In the Milky Way, cosmic rays (CRs) are dynamically important in the interstellar medium, contribute to hydrostatic balance, and may help regulate star formation. However, we know far less about the importance of CRs in galaxies whose gas…

Astrophysics of Galaxies · Physics 2021-01-27 Roland M. Crocker , Mark R. Krumholz , Todd A. Thompson

Cosmic rays (CRs) are an important energy source in the circum-galactic medium (CGM) that impact the multi-phase gas structure and dynamics. We perform two-dimensional CR-magnetohydrodynamic simulations to investigate the role of CRs in…

Astrophysics of Galaxies · Physics 2022-06-14 Xiaoshan Huang , Yan-fei Jiang , Shane W. Davis

(Abridged) X-ray observations of synchrotron rims in supernova remnant (SNR) shocks show evidence of strong magnetic field amplification (a factor of ~100 between the upstream and downstream medium). This amplification may be due to plasma…

High Energy Astrophysical Phenomena · Physics 2014-11-20 Mario A. Riquelme , Anatoly Spitkovsky

Understanding the physical mechanisms that control galaxy formation is a fundamental challenge in contemporary astrophysics. Recent advances in the field of astrophysical feedback strongly suggest that cosmic rays (CRs) may be crucially…

High Energy Astrophysical Phenomena · Physics 2023-10-10 Mateusz Ruszkowski , Christoph Pfrommer

Feedback mediated by cosmic rays (CRs) is an important process in galaxy formation. Because CRs are long-lived and because they are transported along magnetic field lines independently of any gas flow, they can efficiently distribute their…

Astrophysics of Galaxies · Physics 2022-03-24 Timon Thomas , Christoph Pfrommer , Rüdiger Pakmor

Cosmic-ray (CR) feedback is widely recognized as a key regulator of galaxy formation. After being accelerated at supernova remnant shocks, CRs propagate through the interstellar medium (ISM), establishing smooth large-scale distributions…

Astrophysics of Galaxies · Physics 2025-10-21 Timon Thomas , Christoph Pfrommer , Rüdiger Pakmor , Rouven Lemmerz , Mohamad Shalaby

The physics of energetic particle propagation in magnetised environments plays a crucial role in both the processes of acceleration and transport of cosmic rays. Recent theoretical developments in the field of cosmic ray research have been…

High Energy Astrophysical Phenomena · Physics 2018-10-31 Elena Amato , Pasquale Blasi