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Related papers: Features in the Spectrum of Cosmic-Ray Positrons f…

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Recent measurements of cosmic-ray electron and positron spectra at energies from a GeV to 5 TeV, as well as radio, X-ray and a wide range of gamma-ray observations of pulsar-wind nebulae, indicate that pulsars are significant sources of…

High Energy Astrophysical Phenomena · Physics 2018-09-19 Ilias Cholis , Tanvi Karwal , Marc Kamionkowski

Electron and positron fluxes in cosmic rays are currently measured with unprecedented precision by AMS-02 up to TeV energies, and represent unique probes for the local properties of our Galaxy. The interpretation of their spectra is at…

High Energy Astrophysical Phenomena · Physics 2022-09-13 Silvia Manconi

Observations of the TeV halos associated with nearby pulsars indicate that these objects inject significant fluxes of very high-energy electron-positrons pairs into the interstellar medium (ISM), thereby likely providing the dominant…

High Energy Astrophysical Phenomena · Physics 2023-02-17 Olivia Meredith Bitter , Dan Hooper

The Alpha Magnetic Spectrometer (AMS-02) has provided unprecedented precision measurements of the electron and positron cosmic-ray fluxes and the positron fraction spectrum. At the higher energies, sources as energetic local pulsars, may…

High Energy Astrophysical Phenomena · Physics 2023-03-15 Ilias Cholis , Thressay Hoover

Pulsars are believed to be sources of relativistic electrons and positrons. The abundance of detections of gamma-ray millisecond pulsars by Fermi Large Area Telescope coupled with their light curve characteristics that imply copious pair…

High Energy Astrophysical Phenomena · Physics 2015-06-23 C. Venter , A. Kopp , P. L. Gonthier , A. K. Harding , I. Büsching

Recent results from the PAMELA satellite indicate the presence of a large flux of positrons (relative to electrons) in the cosmic ray spectrum between approximately 10 and 100 GeV. As annihilating dark matter particles in many models are…

Astrophysics · Physics 2010-04-15 Dan Hooper , Pasquale Blasi , Pasquale Dario Serpico

AMS-02 recently published its lepton spectra measurement. The results show that the positron fraction no longer increases above $\sim$200 GeV. The aim of this work is to investigate the possibility that the excess of positron fraction is…

High Energy Physics - Phenomenology · Physics 2016-04-28 Jie Feng , Hong-Hao Zhang

The AMS-02 experiment confirms the excess of positrons in cosmic rays (CRs) for energy above 10 GeV with respect to the secondary production of positrons in the interstellar medium. This is interpreted as evidence of the existence of a…

High Energy Astrophysical Phenomena · Physics 2017-08-23 S Della Torre , M Gervasi , PG Rancoita , D Rozza , A Treves

The AMS-02 collaboration has just published a high precision measurement of the cosmic positron fraction $e^+/(e^- + e^+)$, which rises with energy from $\sim 5$ GeV to $\sim 350$ GeV. The result indicates the existence of primary…

High Energy Astrophysical Phenomena · Physics 2013-08-09 Peng-Fei Yin , Zhao-Huan Yu , Qiang Yuan , Xiao-Jun Bi

Isotropic diffusion is a key assumption in many models of cosmic-ray electrons and positrons. We find that simulation results imply a critical energy of ~10-1000~GeV above which electrons and positrons can spend their entire lives in…

High Energy Astrophysical Phenomena · Physics 2021-10-07 Matthew D. Kistler , Hasan Yuksel , Alexander Friedland

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

We present the results of new calculations of the energy spectra of cosmic ray electrons, positrons and also positron fraction under assumption that both electrons and positrons are generated by the same Galactic sources, which accelerate…

High Energy Astrophysical Phenomena · Physics 2019-05-17 Nikolay Volkov , Anatoly Lagutin , Alexander Tyumentsev

Pulsars have long been studied in the electromagnetic spectrum. Their environments are rich in high-energy cosmic-ray electrons and positrons likely enriching the interstellar medium with such particles. In this work we use recent…

High Energy Astrophysical Phenomena · Physics 2022-01-26 Ilias Cholis , Iason Krommydas

We present a novel calculation of the spectrum of electrons and positrons from random sources, supernova remnants and pulsars, distributed within the spiral arms of the Galaxy. The pulsar emissivity in terms of electron-positron pairs is…

High Energy Astrophysical Phenomena · Physics 2021-04-15 Carmelo Evoli , Elena Amato , Pasquale Blasi , Roberto Aloisio

The cosmic-ray positron flux calculated using the cosmic-ray nuclei interactions in our Galaxy cannot explain observed data above 10 GeV. An excess in the measured positron flux is therefore open to interpretation. Nearby pulsars, located…

High Energy Astrophysical Phenomena · Physics 2017-10-04 Jagdish C. Joshi , Soebur Razzaque

Until fairly recently, it was widely accepted that local cosmic ray spectra were largely featureless power laws, containing limited information on their acceleration and transport. This viewpoint is currently being revised in the light of…

High Energy Astrophysical Phenomena · Physics 2019-08-14 Andrea Vittino , Philipp Mertsch , Henning Gast , Stefan Schael

The positron fraction in cosmic rays was found to be steadily increasing in function of energy, above $\sim$10 GeV. This behaviour contradicts standard astrophysical mechanisms, in which positrons are secondary particles, produced in the…

High Energy Astrophysical Phenomena · Physics 2015-10-27 Mathieu Boudaud

Recent precision measurements of the flux of cosmic ray positrons by the Alpha Magnetic Spectrometer show that the spectrum has a marked softening feature for energies close to one TeV. A possible interpretation of this result is that the…

High Energy Astrophysical Phenomena · Physics 2019-02-19 Paolo Lipari

The measurements of electrons from cosmic rays have begun a new era a few years ago with high precision experiments like PAMELA and Fermi-LAT. The positron fraction seems to indicate an unknown component above the standard background…

High Energy Astrophysical Phenomena · Physics 2017-08-23 Jonathan Pochon

Recent measurements of the Geminga and B0656+14 pulsars by the gamma-ray telescope HAWC (along with earlier measurements by Milagro) indicate that these objects generate significant fluxes of very high-energy electrons. In this paper, we…

High Energy Astrophysical Phenomena · Physics 2017-11-22 Dan Hooper , Ilias Cholis , Tim Linden , Ke Fang
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