Pulsars as the sources of high energy cosmic ray positrons

Journal Article · Thu Jan 15 04:00:00 EST 2009 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2009/01/025· OSTI ID:22156864

Hooper, Dan; Blasi, Pasquale ^[1]

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1. Theoretical Astrophysics, Fermi National Accelerator Laboratory, Batavia U.S.A. (United States)

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 predicted to contribute to the cosmic ray positron spectrum in this energy range, a great deal of interest has resulted from this observation. Here, we consider pulsars (rapidly spinning, magnetized neutron stars) as an alternative source of this signal. After calculating the contribution to the cosmic ray positron and electron spectra from pulsars, we find that the spectrum observed by PAMELA could plausibly originate from such sources. In particular, a significant contribution is expected from the sum of all mature pulsars throughout the Milky Way, as well as from the most nearby mature pulsars (such as Geminga and B0656+14). The signal from nearby pulsars is expected to generate a small but significant dipole anisotropy in the cosmic ray electron spectrum, potentially providing a method by which the Fermi gamma-ray space telescope would be capable of discriminating between the pulsar and dark matter origins of the observed high energy positrons.

• OSTI ID: 22156864
• Journal Information: Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 01 Vol. 2009; ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ANISOTROPY
COSMIC POSITRONS
ELECTRON SPECTRA
GAMMA RADIATION
GEV RANGE 10-100
MILKY WAY
NEUTRON STARS
NONLUMINOUS MATTER
PULSARS
TELESCOPES