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Related papers: Cosmic Ray e^+/(e^- + e^+) and pbar/p Ratios Expla…

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We study in detail the effect of different particle release times from sources on the cosmic-ray (CR) spectrum below $10^{15}eV$ in the Galaxy. We discuss different possible forms of particle injection such as burst-like injection,…

Astrophysics · Physics 2008-11-26 Satyendra Thoudam

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 cosmic-ray flux of positrons is measured with high precision by the space-borne particle spectrometer AMS-02. The hypothesis that pulsar wind nebulae (PWNe) can significantly contribute to the excess of the positron ($e^+$) cosmic-ray…

High Energy Astrophysical Phenomena · Physics 2021-12-08 Luca Orusa , Silvia Manconi , Fiorenza Donato , Mattia Di Mauro

The theory of diffusive particle acceleration explains the spectral properties of the cosmic rays below energies of approx. 10^6 GeV as produced at strong shocks in supernova remnants (SNR's). To supply the observed flux of cosmic rays, a…

Astrophysics · Physics 2007-05-23 U. D. J. Gieseler , T. W. Jones , Hyesung Kang

A fundamental problem of cosmic ray (CR) physics is the determination of the average properties of Galactic CRs outside the Solar system. Starting from COS-B data in the 1980's, gamma-ray observations of molecular clouds in the Gould Belt…

High Energy Astrophysical Phenomena · Physics 2015-06-05 M. Kachelriess , S. Ostapchenko

The standard approach to cosmic-ray (CR) propagation in the Galaxy is based on the assumption that local transport properties can be extrapolated to the whole CR confining volume. Such models tend to underestimate the gamma-ray flux above…

High Energy Astrophysical Phenomena · Physics 2015-05-06 Daniele Gaggero , Alfredo Urbano , Mauro Valli , Piero Ullio

The proof of cosmic ray (CR) origin in supernova remnants (SNR) must hinge on full consistency of the CR acceleration theory with the observations; direct proof is impossible because of the orbit stochasticity of CR particles. Recent…

Astrophysics of Galaxies · Physics 2016-10-11 M. A. Malkov , P. H. Diamond , R. Z. Sagdeev

We consider the galactic population of gamma-ray pulsars as possible sources of cosmic rays at and just above the ``knee'' in the observed cosmic ray spectrum at $10^{15}$--$10^{16}$ eV. We suggest that iron nuclei may be accelerated in the…

Astrophysics · Physics 2008-11-26 W. Bednarek , R. J. Protheroe

We are constructing a model which aims to reproduce observational data of many kinds related to cosmic-ray origin and propagation: direct measurements of nuclei, antiprotons, electrons and positrons, gamma-rays, and synchrotron radiation.…

Astrophysics · Physics 2007-05-23 A. W. Strong , I. V. Moskalenko

The contribution of the Source Cosmic Rays (SCRs), confined in Supernova Remnants, to the diffuse high energy \gr emission above 1 GeV from the Galactic disk is studied. \grs produced by the SCRs have a much harder spectrum compared with…

Astrophysics · Physics 2010-12-03 Evgeny G. Berezhko , Heinrich J. Voelk

We have developed a model which aims to reproduce observational data of many kinds related to cosmic-ray (CR) origin and propagation: direct measurements of nuclei, antiprotons, electrons and positrons, gamma-rays, and synchrotron…

Astrophysics · Physics 2009-10-31 I. V. Moskalenko , A. W. Strong

We examine the question of the origin of the Galactic cosmic-rays (GCRs) in the light of the data available at the highest energy end of the spectrum. We argue that the data of the Pierre Auger Observatory and of the KASCADE-Grande…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Etienne Parizot

The spectra fits to a sample of 34 supernova remnants (Zeng et al., 2019) are updated. $\gamma$-ray spectra of 20 supernova remnants (SNRs) with a soft TeV spectrum are further analyzed. We found that 17 of them can be fitted in the…

High Energy Astrophysical Phenomena · Physics 2019-11-20 Houdun Zeng , Yuliang Xin , Qi Fu , Siming Liu

It is presumed that the observed cosmic rays up to about $3\times 10^{18}$ eV are of Galactic origin, the particles being the ones which are found in the composition of the stellar winds of stars that explode as supernova into the…

Astrophysics · Physics 2007-05-23 Adrian Sabin Popescu

Supernova remnants (SNRs) are thought to be the primary sources of Galactic Cosmic Rays (CRs). In the last few years, the wealth of gamma-ray data collected by GeV and TeV instruments has provided important information about particle…

High Energy Astrophysical Phenomena · Physics 2016-11-02 Martina Cardillo , Elena Amato , Pasquale Blasi

Supernovae (SNe) with strong interactions with circumstellar material (CSM) are promising candidate sources of high-energy neutrinos and gamma rays, and have been suggested as an important contributor to Galactic cosmic rays beyond 1 PeV.…

High Energy Astrophysical Phenomena · Physics 2019-03-27 Kohta Murase , Anna Franckowiak , Keiichi Maeda , Raffaella Margutti , John F. Beacom

Recent direct measurements of Galactic cosmic ray spectra by balloon/space-borne detectors reveal spectral hardenings of all major nucleus species at rigidities of a few hundred GV. The all-sky diffuse gamma-ray emissions measured by the…

High Energy Astrophysical Phenomena · Physics 2018-03-21 Yi-Qing Guo , Qiang Yuan

The diffuse galactic gamma-ray spectrum measured by the EGRET experiment \citep{Hunter:1997} are interpreted within a scenario in which cosmic rays (CRs) are injected by three different kind of sources, (i) supernovae (SN) which explode…

Astrophysics · Physics 2007-05-23 Sabrina Casanova , Peter L. Biermann , Ralph Engel , Athina Meli , Ralf Ulrich

We revisit the idea that the Galactic center (GC) is the dominant source of Galactic cosmic rays (GCRs), based on a series of new observational evidence. A unified model is proposed to explain the new phenomena of GCRs and $\gamma$-rays…

High Energy Astrophysical Phenomena · Physics 2013-01-24 Yiqing Guo , Zhaoyang Feng , Qiang Yuan , Cheng Liu , Hongbo Hu

We study the propagation and injection models of cosmic rays using the latest measurements of the Boron-to-Carbon ratio and fluxes of protons, Helium, Carbon, and Oxygen nuclei by the Alpha Magnetic Spectrometer and the Advanced Composition…

High Energy Astrophysical Phenomena · Physics 2018-11-13 Qiang Yuan