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An exact turbulence universal scaling law-8/3 for the density fluctuations of cosmic ray (CR) is obtained on the basis of a new analytical compressible turbulence theory and known two-fluid model of the CR dynamics. It is shown that the…

High Energy Astrophysical Phenomena · Physics 2022-02-11 Artem S. Chefranov , Sergey G. Chefranov , Georgy S. Golitsyn

We study transport of GeV cosmic rays (CRs) in a set of high-resolution TIGRESS magnetohydrodynamic simulations of the star-forming interstellar medium (ISM). Our local disk patch models sample a wide range of gas surface densities,…

Astrophysics of Galaxies · Physics 2025-09-04 Ronan Hix , Lucia Armillotta , Eve Ostriker , Chang-Goo Kim

Cosmic rays (CR), constrained by scattering on magnetic irregularities, are believed to propagate diffusively. But a well-known defect of diffusive approximation whereby some of the particles propagate unrealistically fast has directed…

High Energy Astrophysical Phenomena · Physics 2016-10-11 Mikhail Malkov , Roald Sagdeev

The majority of galactic baryons reside outside of the galactic disk in the diffuse gas known as the circumgalactic medium (CGM). While state-of-the art simulations excel at reproducing galactic disk properties, many struggle to drive…

Astrophysics of Galaxies · Physics 2018-12-05 Iryna Butsky , Thomas R. Quinn

Stars and planets form within cold, dark molecular clouds. In these dense regions, where starlight cannot penetrate, cosmic rays (CRs) are the dominant source of ionization -- driving interstellar chemistry(Dalgarno (2006, PNAS, 103,…

A new nonthermal phenomenon caused by streaming cosmic rays (CRs) in the universe is proposed. The streaming CRs drive the return current of thermal electrons to compensate for the CR current. Then, electric fields are induced by the…

High Energy Astrophysical Phenomena · Physics 2022-04-27 Yutaka Ohira

Cosmic rays scatter off magnetic irregularities (Alfven waves) with which they are resonant, that is waves of wavelength comparable to their gyroradii. These waves may be generated either by the cosmic rays themselves, if they stream faster…

Astrophysics · Physics 2009-11-10 Alison J. Farmer , Peter Goldreich

We revisit propagation of galactic cosmic rays (CRs) in light of recent advances in CR diffusion theory in realistic interstellar turbulence. We use a tested model of turbulence in which it has been shown that fast modes dominate scattering…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Carmelo Evoli , Huirong Yan

We recently found that streaming cosmic rays (CRs) induce a resistive electric field that can accelerate secondary electrons produced by CR ionization. In this work, we study the evolution of the energy spectrum of secondary electrons by…

High Energy Astrophysical Phenomena · Physics 2024-06-26 Yutaka Ohira

Cosmic ray propagation is determined by the properties of interstellar turbulence. The multiphase nature of interstellar medium (ISM) and diversity of driving mechanisms give rise to spatial variation of turbulence properties. Meanwhile,…

High Energy Astrophysical Phenomena · Physics 2021-09-21 Huirong Yan

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

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

Dark radiation (DR) appears as a new physics candidate in various scenarios beyond the Standard Model. While it is often assumed that perturbations in DR are adiabatic, they can easily have an isocurvature component if more than one field…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-18 Subhajit Ghosh , Soubhik Kumar , Yuhsin Tsai

Cosmic rays (CRs) control the thermal, ionization and chemical state of the dense H_2 gas regions that otherwise remain shielded from far-UV and optical stellar radiation propagating through the dusty ISM of galaxies. It is in such…

High Energy Astrophysical Phenomena · Physics 2015-06-05 Padelis P. Papadopoulos , Wing-Fai Thi

Within the classical convection--diffusion approximation, we show that the angular distribution of cosmic rays (CRs) in a highly turbulent flow may exhibit significant small-scale anisotropies. The CR intensity angular power spectrum $…

High Energy Astrophysical Phenomena · Physics 2024-02-27 Yiran Zhang , Siming Liu

To investigate the interstellar medium (ISM) and Galactic cosmic rays (CRs) in the solar neighborhood, we analyzed ${\gamma}$-ray data by Fermi Large Area Telescope (LAT) for five nearby molecular cloud regions. Our data includes the…

High Energy Astrophysical Phenomena · Physics 2025-06-23 Tsunefumi Mizuno , Katsuhiro Hayashi , Hinako Ochi , Igor V. Moskalenko , Elena Orlando , Andrew W. Strong

We employed our recent model of the cosmic-ray (CR) halo to compute the Galactic spectra of stable and unstable secondary nuclei. In this model, confinement of the Galactic CRs is entirely determined by the self-generated Alfvenic…

Astrophysics of Galaxies · Physics 2024-06-13 D. O. Chernyshov , A. V. Ivlev , V. A. Dogiel

Cosmic rays (CRs) are an important component in the interstellar medium (ISM), but their effect on the dynamics of the disk-halo interface (< 10 kpc from the disk) is still unclear. We study the influence of CRs on the gas above the disk…

Context: Molecular data of extreme environments, such as Arp 220, but also NGC 253, show evidence for extremely high cosmic ray (CR) rates (10^3-10^4 * Milky Way) and mechanical heating from supernova driven turbulence. Aims: The…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 R. Meijerink , M. Spaans , A. F. Loenen , P. P. van der Werf

It is expected that cosmic rays (CRs) escape from high-redshift galaxies at redshift $z\sim 10 \, - \, 20$ because CRs are accelerated by supernova remnants of the first stars. Although ultraviolet and X-ray photons are widely considered…

High Energy Astrophysical Phenomena · Physics 2023-06-07 Shota L. Yokoyama , Yutaka Ohira
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