Search for low energetic neutrino signals from Galactic Supernovae and collisionally heated Gamma-Ray Bursts with the IceCube Neutrino Observatory

• Main Author: Baum, Volker
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Johannes Gutenberg-Universität Mainz 2017
• Subjects: ddc:530; Antarctic; South Pole; The Antarctic; Antarc*; South pole
• Online Access: https://openscience.ub.uni-mainz.de/handle/20.500.12030/1374; https://hdl.handle.net/20.500.12030/1374; https://doi.org/10.25358/openscience-1372

The IceCube Neutrino Observatory, located in the glacial ice beneath the geographic South Pole, surveys a one cubic kilometer volume in the Antarctic ice for particle interactions. This detector volume is monitored by 5160 digital optical modules, each equipped with a photomultiplier tube as sensor. Within the last years, most studies with the IceCube detector were focused on searches for high-energy neutrinos that do not arise from cosmic ray interactions in the atmosphere. These efforts eventually lead to the detection of an astrophysical neutrino flux manifesting in events with energies at the 1-10 PeV energy range. This work, in contrast, focuses on the low-energy regime below 1 TeV. Therefore, not only events recorded by the IceCube detector are investigated, but also those detected by its low-energy extension DeepCore that has a minimal energy threshold of 10 GeV. The sources in this low-energy regime that will be investigated within this work are Supernovae (SNe) and Gamma-Ray Bursts (GRBs). Supernovae emit neutrinos with energies of O(MeV) and are detectable with IceCube by statistical methods within our Galaxy and the Magellanic Clouds. With the improvements presented in this work, the detection probability of SNe in the Magellanic Clouds was increased by a factor of six. Major aspect of the introduced improvements is an efficient realtime correction for the dominating background of atmospheric muons. GRBs are predicted to produce neutrinos of 10 -100 GeV via the newly proposed inelastic collision mechanism. Of particular interest for this work is a source class that may constitute a possible connection between supernovae and GRBs, the so-called GRB-SN class. In this context, new upper limits were set on the neutrino flux from galactic supernovae with the particular progenitor type required for GRB-SNe as well as on the neutrino flux expected from GRBs described by the inelastic collision model. Finally, a search for coincidences between high-significant SN candidates and events that are on-time with ...