Searching for WIMPs in Deep Radio Observations of Galactic dSphs
Abstract
Weakly Interacting Massive Particles (WIMPs) are attractive dark matter candidates, and indirect searches for radiation resulting from their annihilations into Standard Model particles are a promising approach for constraining WIMP properties. While gamma-ray searches for neutral pion decays have been widely exploited, energy losses from charged annihilation products should also produce detectable signals. In this talk, I will present deep radio observations designed to detect degree-scale radio synchrotron halos in galactic dwarf spheroidal galaxies (dSphs), predicted to stem from electron and positron annihilation products spiraling in turbulent magnetic fields. I will describe i. the technical challenges associated with obtaining wide-field radio maps with sensitivities below the astrophysical confusion limit, ii. the theoretical challenges of modelling charged particle diffusion in dSphs, and iii. the prospects for overcoming these challenges. I will argue that despite these challenges, non-detections in our maps imply upper limits on the WIMP annihilation cross-section that rival those obtained by gamma-ray searches: deep radio observations of dSphs are highly complementary to indirect WIMP searches at higher energies.
- Publication:
-
Probes of Dark Matter on Galaxy Scales
- Pub Date:
- July 2013
- Bibcode:
- 2013pdmg.conf30103S