Speaker: Alex Pizzuto, Physics PhD Graduate Student
Abstract: Ever since the first observation of cosmic rays over a century ago, the origins of these high-energy particles has remained a mystery. Identifying and understanding the sources of these cosmic rays could provide invaluable insight into not only astrophysics but also fundamental particle physics. The IceCube Neutrino Observatory, a cubic-kilometer neutrino telescope instrumented at the geographic South Pole, has made remarkable progress on this front -- first with the detection of a diffuse astrophysical neutrino flux in 2013, and later with the identification of a particular flaring blazar as a promising neutrino source. However, the sources of the vast majority of the diffuse neutrino flux remain unidentified. The goal of this thesis is to identify astrophysical neutrino sources despite our limited detection threshold. We show how analyzing neutrino data with new techniques can reveal an immense deal about the nature of the universe's most energetic particle accelerators. After providing a description of the state of the field and a quick overview of the general analysis techniques used, we present a variety of analyses focused on searching for neutrino emission from promising classes of astrophysical transients. Although all of these analyses resulted in non-detections, we are hopeful that the tools presented here will assist with the identification of cosmic neutrino sources in the years to come.