A possible signature of annihilating dark matter

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2 Citations (Scopus)

Abstract

In this article, we report a new signature of dark matter annihilation based on the radio continuum data of NGC 1569 galaxy detected in the past few decades. After eliminating the thermal contribution of the radio signal, an abrupt change in the spectral index is shown in the radio spectrum. Previously, this signature was interpreted as an evidence of convective outflow of cosmic ray. However, we show that the cosmic ray contribution is not enough to account for the observed radio flux. We then discover that if dark matter annihilates via the 4-e channel with the thermal relic cross-section, the electrons and positrons produced would emit a strong radio flux which can provide an excellent agreement with the observed signature. The best-fitting dark matter mass is 25 GeV. Copyright © 2017 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.
Original languageEnglish
Pages (from-to)2576-2579
JournalMonthly Notices of the Royal Astronomical Society
Volume474
Issue number2
DOIs
Publication statusPublished - 2018

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dark matter
signatures
radio
cosmic rays
radio signals
radio spectra
cosmic ray
positrons
galaxies
continuums
cross sections
outflow
cross section
electrons
electron

Citation

Chan, M. H. (2018). A possible signature of annihilating dark matter. Monthly Notices of the Royal Astronomical Society, 474(2), 2576-2579. doi: 10.1093/mnras/stx2930

Keywords

  • Dark matter