Looking for axion dark matter in dwarf spheroidal galaxies

We study the extent to which the decay of cold dark matter axions can be probed with forthcoming radio telescopes such as the Square Kilometer Array (SKA). In particular, we focus on signals arising from dwarf spheroidal galaxies, where astrophysical uncertainties are reduced and the expected magnetic field strengths are such that signals arising from axion decay may dominate over axion-photon conversion in a magnetic field. We show that with ?100 hr of observing time, SKA could improve current sensitivity by 2–3 orders of magnitude-potentially obtaining sufficient sensitivity to begin probing the decay of cold dark matter axions.