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Galactic transport models for cosmic rays involve the diffusive motion of these particles in the interstellar medium. Due to the large-scale structured galactic magnetic field this diffusion is anisotropic with respect to the local field…

High Energy Astrophysical Phenomena · Physics 2013-06-07 Frederic Effenberger , Horst Fichtner , Klaus Scherer , Ingo Büsching

Severity of warming predicted by climate models depends on their Transient Climate Response (TCR). Inter-model spread of TCR has persisted at ~100% of its mean for decades. Existing observational constraints of TCR are based on observed…

Atmospheric and Oceanic Physics · Physics 2023-12-25 King-Fai Li , Ka-Kit Tung

We consider the rate of ionization of diffuse and molecular clouds in the interstellar medium by Galactic cosmic rays (GCR) in order to constrain its low energy spectrum. We extrapolate the GCR spectrum obtained from PAMELA at high energies…

Astrophysics of Galaxies · Physics 2015-06-04 Biman B. Nath , Nayantara Gupta , Peter L. Biermann

We study the effects of escaping cosmic rays (CRs) on the interstellar medium (ISM) around their source with spherically symmetric CR-hydrodynamical simulations taking into account the evolution of the CR energy spectrum, radiative cooling,…

High Energy Astrophysical Phenomena · Physics 2026-04-07 Jiro Shimoda , Katsuaki Asano , Shu-ichiro Inutsuka

Based on theoretical and experimental consideration of the first (the Twomey effect) and second indirect aerosol effects the quasianalytic description of physical connection between the galactic cosmic rays intensity and the Earth's cloud…

Galactic cosmic rays (CRs) are accelerated by astrophysical shocks, primarily supernova remnants (SNRs), via diffusive shock acceleration (DSA), an efficient mechanism that predicts power-law energy distributions of CRs. However,…

High Energy Astrophysical Phenomena · Physics 2021-09-24 Rebecca Diesing , Damiano Caprioli

The spectral data on the diffuse Galactic gamma-rays, at medium and high latitudes (|b| > 10) and energies of 1-100 GeV, recently published by the Fermi Collaboration are used to produce a novel study on the gamma-ray emissivity in the…

High Energy Astrophysical Phenomena · Physics 2011-10-28 Maryam Tavakoli , Ilias Cholis , Carmelo Evoli , Piero Ullio

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

Cosmic ray propagation is diffusive because of pitch angle scattering by waves. We demonstrate that if the high-amplitude magnetohydrodynamic turbulence with $\tilde B/\langle B\rangle \sim 1$ is present on top of the mean field gradient,…

High Energy Astrophysical Phenomena · Physics 2015-09-30 Mikhail V. Medvedev , Viktor V. Medvedev

We investigate the anisotropic diffusion of cosmic rays in the large-scale Galactic magnetic field, where diffusion occurs at different rates along and across the magnetic field lines. To model this process, we use stochastic differential…

High Energy Astrophysical Phenomena · Physics 2025-06-17 Ala'a AL-Zetoun

A two-dimensional, time-dependent numerical model is used to calculate the modulation of cosmic rays in the heliosphere. Computations are compared to spacecraft observations in the inner and outer heliosphere. It is shown that the model…

High Energy Astrophysical Phenomena · Physics 2013-10-22 Rex Manuel , Stefan Ferreira , Marius Potgieter

Under nonuniform convection, the distribution of diffusive particles can exhibit dipole and quadrupole anisotropy induced by the fluid inertial and shear force, respectively. These convection-related anisotropies, unlike the Compton-Getting…

High Energy Astrophysical Phenomena · Physics 2022-10-26 Yiran Zhang , Siming Liu , Dejin Wu

The physics of Cosmic ray (CR) transport remains a key uncertainty in assessing whether CRs can produce galaxy-scale outflows consistent with observations. In this paper, we elucidate the physics of CR-driven galactic winds for CR transport…

Astrophysics of Galaxies · Physics 2021-11-24 Eliot Quataert , Todd A. Thompson , Yan-Fei Jiang

This paper studies cosmic ray (CR) transport in magneto hydrodynamic (MHD) turbulence. CR transport is strongly dependent on the properties of the magnetic turbulence. We perform test particle simulations to study the interactions of CR…

High Energy Astrophysical Phenomena · Physics 2022-02-23 Snehanshu Maiti , Kirit Makwana , Heshou Zhang , Huirong Yan

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

Observations of diffuse Galactic gamma-ray spectrum by the EGRET instrument reveal an excess above ~ 1 GeV over the expected gamma-ray spectrum calculated under the assumption that the locally observed cosmic-ray (CR) spectra represent the…

Astrophysics · Physics 2009-11-11 Thoudam Satyendra

The High Altitude Water Cherenkov (HAWC) array is sensitive to high energy Cosmic Rays (CR) in the $\sim 10$ to $\sim 200$ TeV energy range, making it possible to construct maps of the so called "Sun Shadow" ($SS$), i. e. of the deficit of…

Solar and Stellar Astrophysics · Physics 2019-08-21 Alejandro Lara , Paulina Colin , K. P. Arunbabu , James Ryan

Most of the diffuse Galactic GeV gamma-ray emission is produced via collisions of cosmic ray (CR) protons with ISM protons. As such the observed spectra of the gamma-rays and the CRs should be strongly linked. Recent observations of…

High Energy Astrophysical Phenomena · Physics 2017-02-01 Lara Nava , David Benyamin , Tsvi Piran , Nir J. Shaviv

Context. In order to understand galaxy evolution, it is essential to measure star formation rates (SFRs) across Cosmic times. Aims. The use of radio continuum emission as an extinction-free star formation tracer necessitates a good…

Astrophysics of Galaxies · Physics 2023-09-13 V. Heesen , S. Schulz , M. Brüggen , H. Edler , M. Stein , R. Paladino , A. Boselli , A. Ignesti , M. Fossati , R. -J. Dettmar