A Multimessenger Portrait of Stellar Death: Unifying the Neutrino and Gravitational-Wave Signatures of Core-Collapse Supernovae

Abstract

While core-collapse supernovae (CCSNe) are some of the most energetic events in the universe and are responsible for creating the heavy elements we see today, there still remains much to learn regarding the CCSN mechanism. The challenge arises primarily due to the fact that characterizing these events requires a thorough understanding of the simultaneous effects of particle, nuclear, and gravitational physics. The interdisciplinary nature of these events, however, also means that CCSNe are some of few astrophysical events capable of producing electromagnetic, neutrino, as well as gravitational-wave (GW) signals observable with current and future detectors. In this thesis, we analyze the neutrino and GW signals from the largest and longest-running suite of three-dimensional CCSN simulations to date. We first analyze the neutrino signals from each model across three different species to understand how information regarding each stage of the CCSN process as well as the properties of the progenitor star can be extracted from the neutrino luminosity and radiated energy. We study the biases associated with observing neutrinos from a CCSN event from one line of sight, and find that these biases generally grow with time and progenitor mass. We then discuss detection prospects of the neutrino signal by convolving the neutrino fluxes from each model with neutrino detector sensitivities. Next, we analyze the corresponding GW signal and again discuss how CCSN stages and progenitor properties can be gleaned from the GW strain and radiated energy, as well as highlight the possibility of detecting the predicted ``gravitational-wave memory'' effect. We then quantify the detection prospects of the GW signal by calculating signal-to-noise, detection ranges, and detection rates for all of our models with current and future GW detectors. Finally, we leverage the "multimessenger'' nature of CCSN events by comparing the neutrino and GW signals to develop strategies to increase the detection efficiency of the GW signal as well as to place constraints on the nuclear equation-of-state. Overall, the goal of this thesis is to begin developing a theoretical framework to interpret and extract information concerning the CCSN mechanism, progenitor properties, and even open questions in fundamental physics from the next nearby CCSN event.