Astrophys. J. 718, L194–L198 (2010)

The IceCube Neutrino Observatory will study high-energy neutrinos produced in distant supernovae and black holes once it is completed, in 2011. Meanwhile, it is already picking up a lot of background cosmic rays.

By spotting elementary particles called muons that appear when cosmic rays strike Earth's atmosphere, Rasha Abbasi and Paolo Desiati at the University of Wisconsin–Madison and their colleagues with the IceCube Collaboration produced the first map of cosmic rays with energies in the multi-teraelectronvolt region in the Southern Hemisphere and detected them preferentially emanating from a particular location. The findings support previous cosmic-ray sky maps made in the Northern Hemisphere, although they do not shed light on the cause of the directional preference, which remains a mystery.