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TY - THES AU - Reimann, René TI - Search for the sources of the astrophysical high-energy muon-neutrino flux with the IceCube neutrino observatory PB - RWTH Aachen University VL - Dissertation CY - Aachen M1 - RWTH-2019-11012 SP - 1 Online-Ressource (xvii, 279 Seiten) : Illustrationen PY - 2019 N1 - Veröffentlicht auf dem Publikationsserver der RWTH Aachen University 2020 N1 - Dissertation, RWTH Aachen University, 2019 AB - Cosmic rays have been measured for more than a century, however, their sources and their acceleration process are still a major open questions in astroparticle physics. Ideal messenger particles and a smoking gun signal for this hadronic acceleration are neutrinos. With the observation of an high-energy astrophysical neutrino flux in 2013 and the confirmation in the independent detection channel of high-energy through-going muon-neutrinos, the IceCube Neutrino Observatory opened a new window to the non-thermal universe. In this thesis we search for point-like sources of the observed astrophysical high-energy muon-neutrino flux. The search is based on a high statistic and high purity data sample taken by the IceCube Neutrino Observatory and contains data from eight years of livetime. The event selection focus on well-reconstructed, up- and through-going muon neutrino events, which are reconstructed with a median angular resolution of ∼ 1<sup>°</sup> at 1 TeV energy and ∼ 0.3<sup>°</sup> at 1 PeV energy. An unbinned likelihood method is used to test celestial positions for the existence of a point-like source. The likelihood method is optimized to sources showing similar characteristics as the observed astrophysical high-energy muon-neutrino flux. The sensitivity on the muon-neutrino flux of a point-like source with an E<sup>−2</sup> spectrum is of the order of E<sup>2</sup> dN/dE = 3 ·10<sup>−13</sup> TeV cm<sup>−2</sup>s<sup>−1</sup> and improves by about ∼ 35% compared to previous published analyses. We perform a scan of the full Northern Hemisphere to search for a point-like source any where in the sky. As this test suffers from the large number of tested positions, in addition, sky positions from a pre-defined source list, motivated by gamma-ray observations, are tested to reduce the number of trials. Both test results are non significant and compatible with only background. We also test for neutrino emission from the source position of the blazar TXS 0506+056 for which a gamma-ray flare has been found in spatial and temporal coincidence with a extreme-high-energy neutrino alert by IceCube. This test results in a p-value of 2.93 LB - PUB:(DE-HGF)11 DO - DOI:10.18154/RWTH-2019-11012 UR - https://publications.rwth-aachen.de/record/773297 ER -