Constraining annihilating dark matter mass by the radio continuum spectral data of NGC4214 galaxy

TL;DR

This study uses radio spectral data from galaxy NGC4214 to set more stringent constraints on annihilating dark matter mass and cross sections, challenging previous interpretations of cosmic-ray excesses.

Contribution

It introduces a method to differentiate dark matter, cosmic-ray, and thermal contributions in radio data, providing tighter constraints on dark matter properties.

Findings

Lower limits on dark matter mass range from 220 GeV to 600 GeV depending on annihilation channel.

Constraints challenge the dark matter explanation for gamma-ray and cosmic-ray excesses in the Milky Way.

Radio data can effectively constrain dark matter properties beyond gamma-ray observations.

Abstract

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.