School of Physics Thesis Dissertation Defense

Presenter:        Hannah Griggs

Title:                     A Hierarchical Approach to Multi-Messenger Gravitational Wave Searches

Date:                    Tuesday, August 13, 2024

Time:                    12:00 p.m.  

Location:           Boggs 1-44 (VizLab)

Virtual Link:     https://gatech.zoom.us/j/97658398309?pwd=MbMSRI9NdeG7l9aokJSSxoFid0bcjk.1

Committee members: 

Dr. Laura Cadonati, School of Physics, Georgia Institute of Technology (advisor)

Dr. David Ballantyne, School of Physics, Georgia Institute of Technology 

Dr. Gongjie Li, School of Physics, Georgia Institute of Technology

Dr. Ignacio Taboada, School of Physics, Georgia Institute of Technology 

Dr. Ryan Fisher, Department of Physics, Computer Science and Engineering , Christopher Newport University

Abstract: 

Abstract: Multi-messenger gravitational wave astronomy became a booming field after the joint detection of GW/GRB 170817. Gamma-ray, x-ray, and neutrinos are good multi-messenger complements to gravitational wave searches. Where gravitational-wave localization can span tens to hundreds of square degrees in the sky, these other messengers tend to have far smaller error regions and their pinpointed time and location of arrival allow for targeted follow-up searches with gravitational wave detectors. In this talk, I investigate these cosmic messengers with LIGO-Virgo-KAGRA gravitational wave data to search for the messengers’ potential progenitor: neutron star or black hole collisions. Matched filtering searches are a key technique in the effort to detect gravitational waves coincident with gamma-ray bursts and fast radio bursts. I begin by reviewing the field of gravitational wave astronomy. I then explore the potential multi-messenger counterparts to gravitational waves: gamma-ray bursts, neutrinos, fast radio bursts, as well as multi-band observations of compact binary merger. I then present my work in multi-messenger searches for gravitational waves with gamma- ray bursts and fast radio bursts in LIGO-Virgo-KAGRA data using the targeted gravitational wave analysis, PyGRB. The principal limiting factor for PyGRB is its computational cost. The cost makes it infeasible to process hundreds of multi-messenger events. So, I will introduce efforts to build a hierarchical search, PyNu, to process these events for follow-up with the established multi-messenger pipeline, PyGRB. The goal is to process larger multi-messenger catalogs than PyGRB while retaining the unique sensitivity offered by targeted matched filtering. I present the methods for PyNu as well as the results of my analysis of its sensitivity to gravitational wave signals. PyNu will improve the reach of PyGRB and expand our view of the multi-messenger sky at an affordable computational cost.