The HEAT telescopes of the Pierre Auger Observatory: status and first data

THE PIERRE AUGER COLLABORATION (AUTOR 434 DE 474); M. TUEROS (COAUTOR)

Beijing

Conferencia; 32nd International Cosmic Ray Conference 2011; 2011

Institute of High Energy Physics, Chinese Academy of Sciences

The southern Pierre Auger Observatory was designed to detect ultrahigh energy cosmic rays above 1018 eV with high accuracy exploiting a hybrid detection technique. A surface array of 1660 water Cherenkov detectors on a 1500 m triangular grid covers an area of 3000 km2 . The atmosphere above the array is viewed by 24 wide angle telescopes. These telescopes observe the faint fluorescence light of the extensive air showers at dark moonless nights, i.e. with a duty cycle of about 15 %. As an enhancement to this baseline design of the Auger Observatory three additional telescopes with elevated field of view were built and now constitute HEAT, the high-elevation Auger telescopes. These telescopes are similar to the 24 other fluorescence telescopes (FD) but can be tilted by 29 degrees upward. They cover an elevation range from 30 to 58 degrees above horizon to enable the unbiased detection of nearby low energy air showers. Especially in combination with the detector information from an infill array of water tanks on a 750 m grid close to the HEAT site the energy range of high quality hybrid air shower measurements is extended down to below 1017 eV. HEAT is fully commissioned and is taking data continuously since September 2009. The status and prospects of HEAT are discussed and first (preliminary) data are presented.