Article révisé par les pairs
Résumé : IceCube monitors one cubic kilometer of deep Antarctic ice with a lattice of 5160 optical sensors in search of neutrino signals from supernovae. Charge secondaries arising from neutrino interactions in the ice produce Cherenkov photons that are registered by photomultipliers in the sensors. Due to subfreezing ice temperatures, their dark rates are particularly low. Therefore a collective rate enhancement introduced by interacting neutrinos in all photomultipliers provides excellent sensitivity for core collapse supernovae of galactic origin. A detailed understanding of the characteristics and temporal changes of the dark rate background has been achieved and cosmic ray induced muons, responsible for the majority of fake supernova candidate triggers, are rejected in real time. An addition to the standard data acquisition allows IceCube to buffer all registered photons in the detector in case of a serious alert. By analyzing such data, a precision determination of the burst onset time and the characteristics of rapidly varying fluxes, as well as estimates of the average neutrino energies and - for supernovae ending in a black hole - of the burst direction may be obtained. Such data are also crucial to characterize details of the noise behavior and of the atmospheric muon background.