Searching for Dark Matter Signals from Local Dwarf Spheroidal Galaxies
  at Low Radio Frequencies in the GLEAM Survey
  The search for emission from weakly interacting massive particle (WIMP) dark
matter annihilation and decay has become a multi-pronged area of research not
only targeting a diverse selection of astrophysical objects, but also taking
advantage of the entire electromagnetic spectrum. The decay of WIMP particles
into standard model particles has been suggested as a possible channel for
synchrotron emission to be detected at low radio frequencies. Here, we present
the stacking analysis of a sample of 33 dwarf spheroidal (dSph) galaxies with
low-frequency (72 - 231 MHz) radio images from the GaLactic and Extragalactic
All-sky Murchison Widefield Array (GLEAM) survey. We produce radial surface
brightness profiles of images centred upon each dSph galaxy with background
radio sources masked. We remove ten fields from the stacking due to
contamination from either poorly subtracted, bright radio sources or strong
background gradients across the field. The remaining 23 dSph galaxies are
stacked in an attempt to obtain a statistical detection of any WIMP-induced
synchrotron emission in these systems. We find that the stacked radial
brightness profile does not exhibit a statistically significant detection above
the 95% confidence level of $\sim$1.5 mJy beam$^{-1}$. This novel technique
shows the potential of using low-frequency radio images to constrain
fundamental properties of particle dark matter.
