Enhancements to the suthern Pierre Auger Observatory

Abstract

The southern Pierre Auger Observatory has been detecting cosmic rays above 1018eV since 2004, exploiting a hybrid air shower detection technique, with 1660 water Cherenkov detectors together with 24 air fluorescence telescopes on a 3000 km2 site. As low energy enhancements to the observatory, 3 additional telescopes with elevated fields of view were built (HEAT). The detector density was increased in the HEAT fields of view by a factor of four in an area of about 25 km2. This setup enables unbiased hybrid data taking above 1017eV. The infilled area is also being equipped with large underground scintillator muon detectors (AMIGA). Finally, a prototype array of radio antenna stations (AERA), working from 30 to 80 MHz, has been installed in a part of the infill. Properties and status of AMIGA, HEAT, and AERA are presented.