English
Related papers

Related papers: Self-consistent theory of cosmic ray penetration i…

200 papers

We study the combined impact of magnetic mirroring and focusing on the ionization by cosmic rays (CRs) in dense molecular clouds and circumstellar disks. We show that for effective column densities of up to $\sim10^{25}$ cm$^{-2}$ (where…

High Energy Astrophysical Phenomena · Physics 2018-08-29 Kedron Silsbee , Alexei V. Ivlev , Marco Padovani , Paola Caselli

The origin of cosmic rays (CRs) and how they propagate remain unclear. Studying the propagation of CRs in magnetohydrodynamic (MHD) turbulence can help to comprehend many open issues related to CR origin and the role of turbulent magnetic…

High Energy Astrophysical Phenomena · Physics 2025-01-10 Na-Na Gao , Jian-Fu Zhang

We use $1$D and $3$D two-fluid cosmic ray (CR) hydrodynamic simulations to investigate the role of CRs in the vicinity of a compact young star cluster. We model a self-gravitating cloud (density profile $\rho \propto r^{-1}$), include…

Astrophysics of Galaxies · Physics 2018-08-08 Siddhartha Gupta , Biman B. Nath , Prateek Sharma

To understand the conditions under which dense, molecular gas is able to form within a galaxy, we post-process a series of three-dimensional galactic-disk-scale simulations with ray-tracing based radiative transfer and chemical network…

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

Acceleration of cosmic-ray electrons (CRe) in the intra-cluster-medium (ICM) is probed by radio observations that detect diffuse, Mpc-scale, synchrotron sources in a fraction of galaxy clusters. Giant radio halos are the most spectacular…

High Energy Astrophysical Phenomena · Physics 2015-09-11 G. Brunetti

Radio bubbles, ubiquitous features of the intracluster medium around active galactic nuclei, are known to rise buoyantly for multiple scale heights through the intracluster medium (ICM). It is an open question how the bubbles can retain…

High Energy Astrophysical Phenomena · Physics 2024-04-09 Robert J. Ewart , Patrick Reichherzer , Archie F. A. Bott , Matthew W. Kunz , Alexander A. Schekochihin

Gamma-ray observations of nearby radio-line-emitting gas structures in the interstellar medium allow us to probe the spectrum of cosmic rays (CRs). In this paper, we analysed Fermi Large Area Telescope (LAT) gamma-ray observations of three…

High Energy Astrophysical Phenomena · Physics 2018-06-15 D. A. Prokhorov , S. Colafrancesco

The observed spectral bump in cosmic-ray (CR) proton and helium spectra, along with the phase and amplitude evolution of CR dipole anisotropy, provide plausible yet indirect evidence for the presence of a nearby CR source. This study…

High Energy Astrophysical Phenomena · Physics 2025-06-25 Xing-Jian Lv , Xiao-Jun Bi , Kun Fang , Peng-Fei Yin , Meng-Jie Zhao

We explore the impact of cosmic rays (CRs) on cosmological adaptive-mesh refinement simulations of a forming 10^12 Msolar halo, focusing on the circumgalactic medium (CGM), and its resulting low-redshift structure and composition. In…

Astrophysics of Galaxies · Physics 2015-12-23 Munier Salem , Greg L. Bryan , Lauren Corlies

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…

The tension between recent observations and theories on cosmic ray (CR) diffusion necessitates exploration of new CR diffusion mechanisms. We perform the first numerical study on the mirror diffusion of CRs that is recently proposed by…

High Energy Astrophysical Phenomena · Physics 2023-12-01 Chao Zhang , Siyao Xu

We report the results of our study of the energy spectra and absolute fluxes of cosmic rays (CRs) in the Local Galaxy based on a five-year $\gamma$-ray observation with the Fermi Large Area Telescope (LAT) of eight nearby giant molecular…

High Energy Astrophysical Phenomena · Physics 2014-07-03 Rui-zhi Yang , Emma de Oña Wilhelmi , Felix Aharonian

The spatial distribution of cosmic ray (CR) particles in the interstellar medium (ISM) is of major importance in radio astronomy, where its knowledge is essential for the interpretation of observations, and in theoretical astrophysics,…

Astrophysics of Galaxies · Physics 2023-06-28 Devika Tharakkal , Andrew P. Snodin , Graeme R. Sarson , Anvar Shukurov

Cosmic rays (CRs) with ~GeV energies can contribute significantly to the energy and pressure budget in the interstellar, circumgalactic, and intergalactic medium (ISM, CGM, IGM). Recent cosmological simulations have begun to explore these…

It is believed that the observed diffuse gamma ray emission from the galactic plane is the result of interactions between cosmic rays and the interstellar gas. Such emission can be amplified if cosmic rays penetrate into dense molecular…

Astrophysics · Physics 2008-11-26 Stefano Gabici , Felix Aharonian , Pasquale Blasi

Context: Diffuse $\gamma$-ray emission from cosmic ray (CR) protons scattering off the gas in the intracluster and intergalactic medium (ICM and IGM) remains out of reach for current observations. Detecting this emission would provide…

High Energy Astrophysical Phenomena · Physics 2025-10-20 Ludwig M. Böss , Ildar Khabibullin , Daniel Karner , Klaus Dolag , Ulrich P. Steinwandel , Elena Hernandez-Martinez , Jenny G. Sorce

Cosmic rays (CRs) with energies $\ll$ TeV comprise a significant component of the interstellar medium (ISM). Major uncertainties in CR behavior on observable scales (much larger than CR gyroradii) stem from how magnetic fluctuations scatter…

High Energy Astrophysical Phenomena · Physics 2024-01-24 Iryna S. Butsky , Philip F. Hopkins , Philipp Kempski , Sam B. Ponnada , Eliot Quataert , Jonathan Squire

Cosmic ray (CR) feedback plays a vital role in shaping the formation and evolution of galaxies through their interaction with magnetohydrodynamic waves. In the CR self-confinement scenario, the waves are generated by the CR gyro-resonant…

High Energy Astrophysical Phenomena · Physics 2025-07-23 Xiaochen Sun , Xue-Ning Bai , Xihui Zhao

We propose a brand-new formalism for the propagation of relativistic cosmic ray (CR) particles. The propagation of CRs has often been described using the diffusion approximation, which has the drawback that the propagation speed of CRs near…

High Energy Astrophysical Phenomena · Physics 2025-05-22 Norita Kawanaka , Rohta Takahashi