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The rapid rise in the cosmic ray positron fraction above 10 GeV, as measured by PAMELA and AMS, suggests the existence of nearby primary sources of high energy positrons, such as pulsars or annihilating/decaying dark matter. In contrast,…

High Energy Astrophysical Phenomena · Physics 2014-03-05 Ilias Cholis , Dan Hooper

In a recent paper (Moskalenko et al., 2002), it has been shown that the flux of secondary cosmic ray (CR) antiprotons appears to be contradictory to measurements of secondary to primary nuclei ratios in cosmic rays when calculated in the…

Astrophysics · Physics 2010-05-27 V. S. Ptuskin , I. V. Moskalenko , F. C. Jones , A. W. Strong , S. G. Mashnik

The ratio between secondary and primary cosmic ray particles is the main source of information about cosmic ray propagation in the Galaxy. Primary cosmic rays are thought to be accelerated mainly in Supernova Remnant (SNR) shocks and then…

High Energy Astrophysical Phenomena · Physics 2019-07-10 Virginia Bresci , Elena Amato , Pasquale Blasi , Giovanni Morlino

High-energy collisions of cosmic-ray nuclei with interstellar gas are believed to be the mechanism producing the majority of cosmic ray antiprotons. Due to the kinematics of the process they are created with a nonzero momentum; the…

Astrophysics · Physics 2010-05-28 I. V. Moskalenko , A. W. Strong , J. F. Ormes , M. S. Potgieter

We calculate the energy spectra of cosmic rays (CR) and their secondaries produced in a supernova remnant (SNR), taking into account the time-dependence of the SNR shock. We model the trajectories of charged particles as a random walk with…

High Energy Astrophysical Phenomena · Physics 2015-05-27 M. Kachelriess , S. Ostapchenko , R. Tomas

High energy collisions of cosmic ray (CR) nuclei with interstellar gas are believed to be the mechanism producing the majority of CR antiprotons. The distinguishing spectral shape with a maximum at 2 GeV and a sharp decrease towards lower…

Astrophysics · Physics 2007-05-23 I. V. Moskalenko , A. W. Strong , J. F. Ormes , M. S. Potgieter , U. W. Langner

We present the energy spectrum of antiproton cosmic ray (CR) component calculated on the basis of the nonlinear kinetic model of CR production in supernova remnants (SNR). The model includes reacceleration of already existing in…

High Energy Astrophysical Phenomena · Physics 2015-01-13 E. G. Berezhko , L. T. Ksenofontov

The spectral shape of cosmic ray positrons and antiprotons has been accurately measured in the broad kinetic energy range 1-350 GeV. In the higher part of this range (E > 30 GeV) the e+ and pbar are both well described by power laws with…

High Energy Astrophysical Phenomena · Physics 2017-03-15 Paolo Lipari

Despite significant efforts over the past decade, the origin of the cosmic ray positron excess has still not been unambiguously established. A popular class of candidate sources are pulsars or pulsar wind nebulae but these cannot also…

High Energy Astrophysical Phenomena · Physics 2021-12-13 Philipp Mertsch , Andrea Vittino , Subir Sarkar

The secondary-to-primary B/C ratio is widely used to study the cosmic ray (CR) propagation processes in the Galaxy. It is usually assumed that secondary nuclei such as Li-Be-B are entirely generated by collisions of heavier CR nuclei with…

High Energy Astrophysical Phenomena · Physics 2012-07-24 N. Tomassetti , F. Donato

Precise measurements of the boron-to-carbon and boron-to-oxygen ratios by DAMPE show clear hardenings around $100$ GeV/n, which provide important implications on the production, propagation, and interaction of Galactic cosmic rays. In this…

High Energy Astrophysical Phenomena · Physics 2023-03-07 Peng-Xiong Ma , Zhi-Hui Xu , Qiang Yuan , Xiao-Jun Bi , Yi-Zhong Fan , Igor V. Moskalenko , Chuan Yue

We discuss the acceleration and escape of secondary particles, especially positrons produced by hadronic interactions in a supernova remnant (SNR) shock. During the shock acceleration, protons would interact with ambient gas and produce…

High Energy Astrophysical Phenomena · Physics 2012-11-01 Norita Kawanaka

The spectrum of cosmic ray protons and electrons released by supernova remnants throughout their evolution is poorly known, because of the difficulty in accounting for particle escape and confinement in the downstream of a shock front,…

High Energy Astrophysical Phenomena · Physics 2021-06-23 P. Cristofari , P. Blasi , D. Caprioli

An excess of $\sim$10-20 GeV cosmic-ray antiprotons has been identified in the spectrum reported by the AMS-02 Collaboration. The systematic uncertainties associated with this signal, however, have made it difficult to interpret these…

High Energy Astrophysical Phenomena · Physics 2019-08-20 Ilias Cholis , Tim Linden , Dan Hooper

Growing evidence reveals universal hardening on various cosmic ray spectra, e.g. proton, positron, as well as antiproton fraction. Such universality may indicate they have a common origin. In this paper, we argue that these widespread…

High Energy Astrophysical Phenomena · Physics 2017-08-02 Wei Liu , Xiao-Jun Bi , Su-Jie Lin , Bing-Bing Wang , Peng-Fei Yin

In the common model supernova shock-acceleration of cosmic rays there are two open questions: 1. where does the high energy cosmic rays below the knee (10$^4-10^6$ Gev) come from, and 2. are cosmic ray accelerated only at their origin or…

Astrophysics · Physics 2007-05-23 Amri Wandel

The excess of continuum gamma-ray emission from the Galaxy above 1 GeV is an unsolved puzzle. It may indicate that the interstellar nucleon or electron spectra are harder than local direct measurements, as could be the case if a local…

Astrophysics · Physics 2011-05-23 I. V. Moskalenko , A. W. Strong , O. Reimer

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 discuss recent observations of high energy cosmic ray positrons and electrons in the context of hadronic interactions in supernova remnants, the suspected accelerators of galactic cosmic rays. Diffusive shock acceleration can harden the…

High Energy Astrophysical Phenomena · Physics 2014-11-20 Markus Ahlers , Philipp Mertsch , Subir Sarkar

In view of the fact that the AMS-02 instrument has recently been used to make preliminary observations of the ratio of the antiprotons (\-{P}) to protons (P) in the primary cosmic radiation we have returned to our idea of signatures of a…

High Energy Astrophysical Phenomena · Physics 2015-10-08 Anatoly Erlykin , Arnold Wolfendale
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