Constraining annihilating dark matter mass by the radio continuum
  spectral data of NGC4214 galaxy
  Recent gamma-ray and radio observations provide stringent constraints for
annihilating dark matter. The current $2\sigma$ lower limits of dark matter
mass can be constrained to $\sim 100$ GeV for thermal relic annihilation cross
section. In this article, we use the radio continuum spectral data of a nearby
galaxy NGC4214 and differentiate the thermal contribution, dark matter
annihilation contribution and cosmic-ray contribution. We can get more
stringent constraints of dark matter mass and annihilation cross sections. The
$5\sigma$ lower limits of thermal relic annihilating dark matter mass obtained
are 300 GeV, 220 GeV, 220 GeV, 500 GeV and 600 GeV for $e^+e^-$, $\mu^+\mu^-$,
$\tau^+\tau^-$, $W^+W^-$ and $b\bar{b}$ channels respectively. These limits
challenge the dark matter interpretation of the gamma-ray, positron and
antiproton excess in our Milky Way.
