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Related papers: Cosmic-ray propagation in molecular clouds

200 papers

Cosmic rays (CR), both solar and Galactic, have an ionising effect on the Earth's atmosphere and are thought to be important for prebiotic molecule production. In particular, the $\rm{H_2}$-dominated atmosphere following an ocean-vaporising…

Earth and Planetary Astrophysics · Physics 2025-05-07 S. R. Raeside , D. Rodgers-Lee , P. B. Rimmer

We calculate the hydrogen and helium-ionizing radiation escaping star-forming molecular clouds, as a function of the star cluster mass and compactness, using a set of high-resolution radiation-magneto-hydrodynamic simulations of star…

Astrophysics of Galaxies · Physics 2020-01-29 Chong-Chong He , Massimo Ricotti , Sam Geen

Recent measurements of cosmic ray proton and helium spectra show a hardening above a few hundreds of GeV. This excess is hard to understand in the framework of the conventional models of Galactic cosmic ray production and propagation. We…

High Energy Astrophysical Phenomena · Physics 2013-10-01 Guilhem Bernard , Timur Delahaye , Yong-Yeon Keum , Wei Liu , Pierre Salati , Richard Taillet

Cosmic-ray scattering on magnetic turbulence leads to spatial diffusive propagation; if the scattering medium is moving, this will inevitably also cause changes in the momentum of the particles, so-called diffusive reacceleration. This can…

High Energy Astrophysical Phenomena · Physics 2015-08-12 Luke O'C. Drury , Andrew W. Strong

We will here discuss how the gamma-ray emission from molecular clouds can be used to probe the cosmic ray flux in distant regions of the Galaxy and to constrain the highly unknown cosmic ray diffusion coefficient. In particular we will…

We develop a theory to account for the cosmic ray spectrum between 1 GeV and 10^4 GeV following the earlier papers of this series. We use the basic concept that the cosmic ray particles are accelerated in a supernova shock that travels…

Astrophysics · Physics 2007-05-23 Peter L. Biermann , Richard G. Strom

We describe a method for the numerical computation of the propagation of primary and secondary nucleons, primary electrons, and secondary positrons and electrons. Fragmentation and energy losses are computed using realistic distributions…

Astrophysics · Physics 2011-05-05 A. W. Strong , I. V. Moskalenko

More and more observations have indicated the existence of slow diffusion phenomena in astrophysical environments, such as around the supernova remnants and pulsar $\gamma$-ray halos, where the diffusion coefficient of cosmic rays (CRs)…

High Energy Astrophysical Phenomena · Physics 2025-06-24 Yawen Xiao , Jianfu Zhang , Siyao Xu

We calculate cosmic ray transport with a collisional Boltzmann Transport Equation, including E-M forces. We apply the Crank-Nicholson Method to solve this equation. At each time step, the spatial distribution of cosmic rays is applied to…

High Energy Astrophysical Phenomena · Physics 2011-10-17 Paul Rimmer , Eric Herbst

In a previous work we investigated the propagation of fast moving charged particles in a spatially constant but slowly time dependent pseudoscalar background, such as the one provided by cold relic axions. The background induces cosmic rays…

High Energy Physics - Phenomenology · Physics 2015-03-17 D. Espriu , F. Mescia , A. Renau

Cosmic rays (CRs) are an integral part of the non-thermal pressure budget in the interstellar medium (ISM) and are the leading-order ionization mechanism in cold molecular clouds. We study the impacts that different microphysical CR…

The recent discovery of diffuse, VHE gamma radiation from the Galactic center ridge by the H.E.S.S. telescope allow for the first time the direct determination of parameters of galactic cosmic ray propagation models. In this paper we show…

Astrophysics · Physics 2008-11-26 I. Büsching , O. C. de Jager , J. Snyman

We investigate the propagation of ultra-high energy cosmic ray nuclei (A = 1-56) from cosmologically distant sources through the cosmic radiation backgrounds. Various models for the injected composition and spectrum and of the cosmic…

Astrophysics · Physics 2014-10-13 Dan Hooper , Subir Sarkar , Andrew M. Taylor

From the rate of hydrogen ionization and the gamma ray flux, we derived the spectrum of relativistic and subrelativistic cosmic rays (CRs) nearby and inside the molecular cloud Sgr B2 near the Galactic Center (GC). We studied two cases of…

High Energy Astrophysical Phenomena · Physics 2015-08-19 V. A. Dogiel , D. O. Chernyshov , A. M. Kiselev , M. Nobukawa , K. S. Cheng , C. Y. Hui , C. M. Ko , K. K. Nobukawa , T. G. Tsuru

We have calculated the dispersion relation for the high energy cosmic rays (protons, electrons and neutrinos) propagating in the Bose gas as well as Bose condensate medium of the pseudo-scalar particles. For cosmic rays propagating in the…

High Energy Physics - Phenomenology · Physics 2009-10-30 Sarira Sahu

Galactic cosmic rays (CRs) play a crucial role in ionisation, dissociation, and excitation processes within dense cloud regions where UV radiation is absorbed by dust grains and gas species. CRs regulate the abundance of ions and radicals,…

We investigate the 1D plane-parallel front connecting the warm ($10^4$ K) and hot ($10^6$ K) phases of the circumgalactic medium (CGM), focusing on the influence of cosmic rays (CRs) in shaping these transition layers. We find that cosmic…

High Energy Astrophysical Phenomena · Physics 2024-10-23 Hanjue Zhu , Ellen G. Zweibel , Nickolay Y. Gnedin

We investigate the diffusion of cosmic rays into molecular cloud complexes. Using the cosmic-ray diffusion formalism of Protheroe, et al. (2008), we examine how cosmic rays diffuse into clouds exhibiting different density structures,…

High Energy Astrophysical Phenomena · Physics 2015-06-22 D. I. Jones

Molecular clouds are expected to emit non-thermal radiation due to cosmic ray interactions in the dense magnetized gas. Such emission is amplified if a cloud is located close to an accelerator of cosmic rays and if cosmic rays can leave the…

Astrophysics · Physics 2009-11-13 Stefano Gabici , Sabrina Casanova , Felix A. Aharonian

Low-frequency radio observations of diffuse synchrotron radiation offer a unique vantage point for investigating the intricate relationship between gas and magnetic fields in the formation of structures within the Galaxy, spanning from the…

Astrophysics of Galaxies · Physics 2024-05-29 Andrea Bracco , Marco Padovani , Daniele Galli