Pulsars versus dark matter interpretation of ATIC/PAMELA

By Dmitry Malyshev, I. Cholis, J. Gelfand. 2009

178 citations recorded by the source corpus.

In this paper, we study the flux of electrons and positrons injected by pulsars and by annihilating or decaying dark matter in the context of recent ATIC, PAMELA, Fermi, and HESS data. We review the flux from a single pulsar and derive the flux from a distribution of pulsars. We point out that the particle acceleration in the pulsar magnetosphere is insufficient to explain the observed excess of electrons and positrons with energy E{approx}1 TeV and one has to take into account an additional acceleration of electrons at the termination shock between the pulsar and its wind nebula. We show that at energies less than a few hundred GeV, the expected flux from a continuous distribution of pulsars provides a good approximation to the expected flux from pulsars in the Australia Telescope National Facility catalog. At higher energies, we demonstrate that the electron/positron flux measured at the Earth will be dominated by a few young nearby pulsars, and therefore the spectrum would contain bumplike features. We argue that the presence of such features at high energies would strongly suggest a pulsar origin of the anomalous contribution to electron and positron fluxes. The absence of features either points to a darkmore » matter origin or constrains pulsar models in such a way that the fluctuations are suppressed. Also we derive that the features can be partially smeared due to spatial variation of the energy losses during propagation.« less

Subfields: Atomic and Molecular Physics, and Optics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/72bb40e98d1ced1de276e8f9dcadc018a849ea8c

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Citations in the corpus

Interpretation of AMS-02 electrons and positrons data (2014, background): “[164], the spectrum of electrons and positrons trapped inside the PWN can be inferred by observing their broadband emission which is due to synchrotron radiation (at low energies) and to inverse Compton (IC) scattering off background photons (at higher energies).”
Galactic electrons and positrons at the Earth: new estimate of the primary and secondary fluxes (2010, methodology): “This has already been noted and described by Malyshev et al. (2009).”
On possible interpretations of the high energy electron–positron spectrum measured by the Fermi Large Area Telescope (2009, background): “It is appropriate mentioning here that in a recent paper (Malyshev et al. 2009 [72]) the authors claim that the possible observation of a smooth electron spectrum by FermiLAT would favour the DM interpretation of those measurements.”
Astrophysical models for the origin of the positron (2011, background): “[120, 121]), or a few prominent nearby sources, like Geminga or Monogem in [74, 77, 122, 117].”
Probing the ATIC peak in the cosmic-ray electron spectrum with H.E.S.S. (2009, methodology): “Combined with the excess in the positron fraction measured by PAMELA (Adriani et al. 2009), the peak feature of the ATIC measurement has been interpreted in terms of a dark matter signal or a contribution of a nearby pulsar (e.g. Malyshev et al. 2009, and references given there).”
Dark matter direct detection signals inferred from a cosmological N-body simulation with baryons (2009, background): “The positron fraction rise observed by PAMELA [20], although striking, can be accommodated in standard astrophysical scenarios with pulsars [33, 34], or with an inhomogeneous distribution of supernovae remnants [35].”