Comment on “Constraining the annihilating dark matter mass by the radio continuum spectral data of the NGC4214 galaxy”

Abstract

In their recent paper, Chan and Lee discuss an interesting possibility: radio continuum emission from a dwarf irregular galaxy may be used to constrain upper limits on the cross section of annihilating dark matter. They claim that the contributions from nonthermal and thermal emission can be estimated with such accuracy that one can place new upper limits on the annihilation cross section. We argue that the observations presented can be explained entirely with a standard spectrum and no contribution from dark matter. As a result, the estimated upper limits of Chan and Lee are at least by a factor of 100 too low.