Towards an Understanding of the Source of Very-High-Energy Astrophysical Neutrinos
Open Access
- Author:
- Senno, Nicholas Benjamin
- Graduate Program:
- Physics
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- July 25, 2017
- Committee Members:
- Peter Istvan Meszaros, Dissertation Advisor/Co-Advisor
Peter Istvan Meszaros, Committee Chair/Co-Chair
Kohta Murase, Committee Member
Miguel Alejandro Mostafa, Committee Member
Jogesh Babu Gutti, Outside Member - Keywords:
- neutrinos
gamma-ray bursts
supernovae
neutrino astronomy - Abstract:
- Over the past five decades, the frontiers of neutrino astronomy have expanded from the Sun’s interior to the Large Magellanic Cloud with the observation of SN 1987A. Recently, the limits of the observable neutrino sky were expanded to include extra-galactic sources with the discovery of ∼ 10 TeV-PeV neutrinos at the IceCube Observatory. In this dissertation, I review the unique properties of neutrinos starting from their hypothesized existence in 1930 and including the phenomena of neutrino flavor oscillations, which resulted in the Nobel Prize in Physics for 2015. I go on to present three astrophysical models—supernovae (SNe) and hypernovae in starburst galaxies, choked jet and low- luminosity Gamma-Ray Bursts, and jetted Tidal Disruption Events—in an attempt to explain the source of the observed diffuse flux of neutrinos. Multi-messenger studies that combine electromagnetic (e.g., gamma-ray) and neutrino observations have begun to rule out gamma-ray bright source models such as starburst galaxies. In chapter 5, I present the first coincidence search between a sub-set of gamma-ray dark transients (Type-Ibc core-collapse SNe) and IceCube neutrino events. Because I do not find a connection between core-collapse SNe, I can place limits on the fraction of the explosion energy that can be converted into cosmic-rays—and ultimately non-thermal very-high-energy neutrinos—as well as the fraction of such SNe that may harbor a jet pointed towards Earth. I conclude this work with a review of very-high-energy neutrino astronomy over the last decade and some future work that may help us to understand what the sources of astrophysical neutrinos are.