Search for short neutrino bursts with IceCube to trigger electromagnetic follow-up

• Main Author: Naab, Richard
• Other Authors: Franckowiak, Anna
• Format: Master Thesis
• Language: English
• Published: 2020
• Subjects: South Pole; South pole
• Online Access: https://bib-pubdb1.desy.de/record/473542; https://bib-pubdb1.desy.de/search?p=id:%22PUBDB-2022-00097%22

The origin of cosmic rays has been a long standing puzzle in astrophysics. Cosmic accelerators are most likely also producing high-energy neutrinos, which are not deflected by magnetic fields and can potentially reveal these sources. The detection of astrophysical neutrinos was achieved with IceCube, a cubic-kilometer in-ice Cherenkov detector which is located at South Pole. This opened the window to multimessenger astronomy, which aims at understanding the non-thermal universe by combining information from cosmic rays, neutrinos, photons and gravitational waves.IceCube’s optical follow-up program aims to probe gamma-ray bursts and choked-jet supernovae as possible neutrino source candidates. Neutrinos with high probability of being of astrophysical origin are used to trigger follow-up searches with optical and X-ray telescopes. Triggers are sent when neutrino events cluster significantly in space and time, which can indicate the presence of astrophysical neutrino signal. Two different algorithms to find clusters of neutrinos are compared in this thesis. A maximum-likelihood approach leads to good results and can be used to extend the optical follow-up program to searches on longer timescales and an extended sky coverage. The sensitivity to a class of hypothetical neutrino sources achieved with the extensions of the follow-up program is finally discussed.