Dark matter annihilation in $\omega$ Centauri: Astrophysical implications derived from the MWA radio data

TL;DR

This study uses MWA radio data to analyze dark matter annihilation signals in $$ Cen, showing current limits can rule out certain models and future improvements could tighten constraints significantly.

Contribution

It applies radio observations to test dark matter annihilation models in $$ Cen, providing new constraints on magnetic fields and diffusion parameters.

Findings

Current radio limits exclude some dark matter models.

Magnetic field strength and diffusion coefficient are constrained.

Future data could significantly tighten these constraints.

Abstract

We present an analysis of Murchison Widefield Array radio telescope data from $\omega$ Cen, possibly a stripped dwarf spheroidal galaxy core captured by our Galaxy. Recent interpretations of Fermi-LAT $\gamma$-ray data by Brown {\it et al.} (2019) and Reynoso-Cordova {\it et al.} (2019) suggest that $\omega$ Cen may contain significant Dark Matter. We utilise their best-fit Dark Matter annihilation models, and an estimate of the magnetic field strength in $\omega$ Cen, to calculate the expected radio synchrotron signal from annihilation, and show that one can usefully rule out significant parts of the magnetic field - diffusion coefficient plane using our current observational limits on the radio emission. Improvement by a factor of 10-100 on these limits could constrain the models even more tightly.