Some recent studies have examined the gamma-ray flux profile of our Galaxy to determine the signal of dark matter annihilation. However, the results are controversial and no confirmation is obtained. In this article, we study the radio flux density profile of the M31 galaxy and show that it could manifest a possible signal of dark matter annihilation. By comparing the likelihoods between the archival observed radio flux density profile data and the predicted radio flux density profile contributed by dark matter and stellar emission, we can constrain the relevant dark matter parameters. Specifically, for the thermal annihilation cross-section via the bb¯ channel, the best-fitting value of dark matter mass is ∼30 GeV, which is consistent with the results of many recent studies. We expect that this method would become another useful way to constrain dark matter, which is complementary to the traditional radio analyses and the other indirect detections. Copyright © 2020 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society.
CitationChan, M. H., Yeung, C. F., Cui, L., & Leung, C. S. (2021). Analysing the radio flux density profile of the M31 galaxy: A possible dark matter interpretation. Monthly Notices of the Royal Astronomical Society, 501(4), 5692-5696. doi: 10.1093/mnras/staa4004
- Dark matter
- Radio continuum: Galaxies