Radio emission from dark matter annihilation in the Large Magellanic Cloud

TL;DR

This paper investigates the potential radio signals from dark matter annihilation in the Large Magellanic Cloud, using observational data to set realistic constraints on dark matter properties.

Contribution

It provides the first detailed estimation of synchrotron emission from dark matter in the LMC, incorporating magnetic field data and energy loss processes for more accurate constraints.

Findings

Set new limits on WIMP mass and annihilation cross section.

Demonstrated the importance of magnetic field and energy loss modeling.

Provided realistic constraints based on extensive observational data.

Abstract

The Large Magellanic Cloud, at only 50 kpc away from us and known to be dark matter dominated, is clearly an interesting place where to search for dark matter annihilation signals. In this paper, we estimate the synchrotron emission due to WIMP annihilation in the halo of the LMC at two radio frequencies, 1.4 and 4.8 GHz, and compare it to the observed emission, in order to impose constraints in the WIMP mass vs. annihilation cross section plane. We use available Faraday rotation data from background sources to estimate the magnitude of the magnetic field in different regions of the LMC's disc, where we calculate the radio signal due to dark matter annihilation. We account for the e+ e- energy losses due to synchrotron, Inverse Compton Scattering and bremsstrahlung, using the observed hydrogen and dust temperature distribution on the LMC to estimate their efficiency. The extensive use of observations, allied with conservative choices adopted in all the steps of the calculation, allow us to obtain very realistic constraints.