Searching for Dark Matter in Messier 33

TL;DR

This paper introduces a novel radio observation method using Messier 33 to set bounds on dark matter properties, leveraging archival data and promising improvements with future high-resolution telescopes.

Contribution

It proposes a new approach to constrain dark matter annihilation parameters through radio continuum observations of Messier 33, especially focusing on a low emitting Radio Cavity.

Findings

Bounds comparable to Milky Way analysis from archival data

Potential to match five-year Fermi LAT bounds with high-resolution radio telescopes

Method can test dark matter origin of electrons and positrons observed by space telescopes

Abstract

Among various approaches for indirect detection of dark matter, synchrotron emission due to secondary electrons/positrons produced in galactic WIMPs annihilation is raising an increasing interest. In this paper we propose a new method to derive bounds in the mchi - <sigmaA*v> plane by using radio continuum observations of Messier 33, paying particular attention to a low emitting Radio Cavity. The comparison of the expected radio emission due to the galactic dark matter distribution with the observed one provides bounds which are comparable to those obtained from a similar analysis of the Milky Way. Remarkably, the present results are simply based on archival data and thus largely improvable by means of specifically tailored observations. The potentiality of the method compared with more standard searches is discussed by considering the optimistic situation of a vanishing flux (within the experimental sensitivity) measured inside the cavity by a high resolution radio telescope like ALMA. Under the best conditions our technique is able to produce bounds which are comparable to the ones expected after five years of Fermi LAT data taking for an hadronic annihilation channel. Furthermore, it allows to test the hypothesis that space telescopes like Pamela and Fermi LAT are actually observing electrons and positrons due to galactic dark matter annihilation into leptons.