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Related papers: CRAFT (Cosmic Ray Acceleration From Turbulence) in…

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Low-energy cosmic rays (CRs) are confined by self-generated MHD waves in the mostly neutral ISM. We show that the CR transport equation can be expressed as a continuity equation for the CR number density involving an effective convection…

Astrophysics · Physics 2009-11-10 Paolo Padoan , John Scalo

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 give a brief review of the origin and acceleration of cosmic rays (CRs), emphasizing the production of CRs at different stages of supernova evolution by the first-order Fermi shock acceleration mechanism. We suggest that supernovae with…

High Energy Astrophysical Phenomena · Physics 2018-01-31 A. M. Bykov , D. C. Ellison , A. Marcowith , S. M. Osipov

Cosmic rays are mostly composed of protons accelerated to relativistic speeds. When those protons encounter interstellar material, they produce neutral pions which in turn decay into gamma rays. This offers a compelling way to identify the…

High Energy Astrophysical Phenomena · Physics 2022-08-17 LAT Collaboration , S. Abdollahi , F. Acero , M. Ackermann , L. Baldini , J. Ballet , G. Barbiellini , D. Bastieri , R. Bellazzini , B. Berenji , A. Berretta , E. Bissaldi , R. D. Blandford , R. Bonino , P. Bruel , S. Buson , R. A. Cameron , R. Caputo , P. A. Caraveo , D. Castro , G. Chiaro , N. Cibrario , S. Ciprini , J. Coronado-Blázquez , M. Crnogorcevic , S. Cutini , F. D'Ammando , S. De Gaetano , N. Di Lalla , F. Dirirsa , L. Di Venere , A. Domínguez , S. J. Fegan , A. Fiori , H. Fleischhack , A. Franckowiak , Y. Fukazawa , P. Fusco , V. Gammaldi , F. Gargano , D. Gasparrini , F. Giacchino , N. Giglietto , F. Giordano , M. Giroletti , T. Glanzman , D. Green , I. A. Grenier , M. -H. Grondin , S. Guiriec , M. Gustafsson , A. K. Harding , E. Hays , J. W. Hewitt , D. Horan , X. Hou , G. Jóhannesson , T. Kayanoki , M. Kerr , M. Kuss , S. Larsson , L. Latronico , M. Lemoine-Goumard , J. Li , F. Longo , F. Loparco , P. Lubrano , S. Maldera , D. Malyshev , A. Manfreda , G. Martí-Devesa , M. N. Mazziotta , I. Mereu , P. F. Michelson , N. Mirabal , W. Mitthumsiri , T. Mizuno , M. E. Monzani , A. Morselli , I. V. Moskalenko , E. Nuss , N. Omodei , M. Orienti , E. Orlando , J. F. Ormes , D. Paneque , Z. Pei , M. Persic , M. Pesce-Rollins , R. Pillera , H. Poon , T. A. Porter , G. Principe , S. Rainò , R. Rando , B. Rani , M. Razzano , S. Razzaque , A. Reimer , O. Reimer , T. Reposeur , M. Sánchez-Conde , P. M. Saz Parkinson , L. Scotton , D. Serini , C. Sgrò , E. J. Siskind , G. Spandre , P. Spinelli , K. Sueoka , D. J. Suson , H. Tajima , D. Tak , J. B. Thayer , D. F. Torres , E. Troja , J. Valverde , Z. Wadiasingh , K. Wood , G. Zaharijas

We investigate numerically the contribution to the cosmic gamma-ray background from cosmic-rays ions and electrons accelerated at intergalactic shocks associated with cosmological structure formation. We show that the kinetic energy of…

Astrophysics · Physics 2008-11-26 Francesco Miniati

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

Understanding the cosmic ray (CR) ionization rate is crucial in order to simulate the dynamics of, and interpret the chemical species observed in molecular clouds. Calculating the CR ionization rate requires both accurate knowledge of the…

High Energy Astrophysical Phenomena · Physics 2019-07-10 Kedron Silsbee , Alexei V. Ivlev

Cosmic rays are charged energetic particles that permeate the interstellar medium. Their sizeable energy share and penetration power makes them essential players in the dynamical and chemical processes that rule Galactic evolution, such as…

High Energy Astrophysical Phenomena · Physics 2026-03-17 Giada Peron , Sarah Recchia , Stefano Menchiari , Alexandre Marcowith , Andrei Bykov , Martin Pohl , Elena Amato

The gamma-ray space telescopes AGILE and Fermi detected short and bright synchrotron gamma-ray flares at photon energies above 100 MeV in the Crab Nebula. This discovery suggests that electron-positron pairs in the nebula are accelerated to…

High Energy Astrophysical Phenomena · Physics 2015-05-30 Benoit Cerutti , Dmitri A. Uzdensky , Mitchell C. Begelman

We analyze the gamma-ray emission from 9 high latitude, translucent molecular clouds taken with the Fermi Large Area Telescope (LAT) between 250 MeV and 10 GeV. Observations of gamma-rays allow us to probe the density and spectrum of cosmic…

High Energy Astrophysical Phenomena · Physics 2015-05-27 R. D. Abrahams , T. A. D. Paglione

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

We discuss processes in galactic cosmic ray (GCR) acceleration sites - supernova remnants, compact associations of young massive stars, and superbubbles. Mechanisms of efficient conversion of the mechanical power of the outflows driven by…

High Energy Astrophysical Phenomena · Physics 2012-12-11 A. M. Bykov , D. C. Ellison , P. E. Gladilin , S. M. Osipov

It has been shown that supernova blast waves interacting with winds from massive stars in compact star clusters may be capable of producing cosmic-ray (CR) protons to above $10^{17}$ eV. We give a brief description of the…

High Energy Astrophysical Phenomena · Physics 2019-12-13 A. M. Bykov , M. E. Kalyashova , D. C. Ellison , S. M. Osipov

We carry out a suite of simulations of the evolution of cosmic-ray (CR) driven, radiatively-cooled cold clouds embedded in hot material, as found in galactic outflows. In such interactions, CRs stream towards the cloud at the Alfv\'en…

Astrophysics of Galaxies · Physics 2020-12-16 Marcus Brüggen , Evan Scannapieco

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 are an essential ingredient in the evolution of the interstellar medium, as they dominate the ionisation of the dense molecular gas, where stars and planets form. However, since they are efficiently scattered by the galactic…

Astrophysics of Galaxies · Physics 2014-09-05 Solenn Vaupré , Pierre Hily-Blant , Cecilia Ceccarelli , Guillaume Dubus , Stefano Gabici , Thierry Montmerle

Data obtained in the ATIC-2 (Advanced Thin Ionization Calorimeter), CREAM (Cosmic Ray Energetics and Mass)) and PAMELA (Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics) experiments suggest that elemental interstellar…

High Energy Astrophysical Phenomena · Physics 2015-06-12 V. S. Ptuskin , V. N. Zirakashvili , E. S. Seo

Recent observations of gamma-rays with the Fermi Large Area Telescope (LAT) in the direction of the inner Galaxy revealed a mysterious GeV excess. Its intensity is significantly above predictions of the standard model of cosmic rays (CRs)…

High Energy Astrophysical Phenomena · Physics 2021-08-10 Dmitry O. Chernyshov , Andrei E. Egorov , Vladimir A. Dogiel , Alexei V. Ivlev

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…

Our Galaxy is the largest nuclear interaction experiment which we know, because of the interaction between cosmic ray particles and the interstellar material. Cosmic rays are particles, which have been accelerated in the Galaxy or in…

Astrophysics · Physics 2011-04-15 Peter L. Biermann