A self-consistent model of cosmic-ray fluxes and positron excess: Roles of nearby pulsars and a sub-dominant source population

Jagdish C. Joshi, Soebur Razzaque

Research output: Contribution to journalArticlepeer-review

11 Citations (Scopus)

Abstract

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 within sub-kiloparsec range of the Solar system, are often invoked as plausible sources contributing to the excess. We show that an additional, sub-dominant population of sources together with the contributions from a few nearby pulsars can explain the latest positron excess data from the Alpha Magnetic Spectrometer (AMS). We simultaneously model, using the DRAGON code, propagation of cosmic-ray proton, Helium, electron and positron and fit their respective flux data. Our fit to the Boron to Carbon ratio data gives a diffusion spectral index of 0.45, which is close to the Kraichnan turbulent spectrum.

Original languageEnglish
Article number029
JournalJournal of Cosmology and Astroparticle Physics
Volume2017
Issue number9
DOIs
Publication statusPublished - 20 Sept 2017

Keywords

  • absorption and radiation processes
  • cosmic ray theory

ASJC Scopus subject areas

  • Astronomy and Astrophysics

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