Acoustic transient event reconstruction and sensitivity studies with the South Pole Acoustic Test Setup

Abstract: The South Pole Acoustic Test Setup (SPATS) consists of four strings instrumented with seven acoustic sensors and transmitters each, which are deployed in the upper 500 m of the IceCube holes. Since end of August 2008 SPATS is operating in transient mode, where three sensor channels of each string, located at three different depth levels, are used for triggered data taking within the 10 to 100 kHz frequency range. This allows to reconstruct the position of the source of acoustic signals in the antarctic ice with high precision. Acoustic signals from re-freezing IceCube holes are identified. All detected acoustic events seen are associated to sources caused by human activities at the South Pole. Further, the sensitive volume for neutrino interactions outside the IceCube instrumented area has been determined by simulation and a flux limit for high energy neutrinos was derived.