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Searching for the Astrophysical Gravitational-Wave Background and Prompt Radio Emission from Compact Binaries


Callister, Thomas Alfred, III (2020) Searching for the Astrophysical Gravitational-Wave Background and Prompt Radio Emission from Compact Binaries. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/xthf-1p70.


Gravitational-wave astronomy is now a reality. During my time at Caltech, the Advanced LIGO and Virgo observatories have detected gravitational waves from dozens of compact binary coalescences. All of these gravitational-wave events occurred in the relatively local Universe. In the first part of this thesis, I will instead look towards the remote Universe, investigating what LIGO and Virgo may be able to learn about cosmologically-distant compact binaries via observation of the stochastic gravitational-wave background. The stochastic gravitational-wave background is composed of the incoherent superposition of all distant, individually-unresolvable gravitational-wave sources. I explore what we learn from study of the gravitational-wave background, both about the astrophysics of compact binaries and the fundamental nature of gravitational waves. Of course, before we can study the gravitational-wave background we must first detect it. I therefore present searches for the gravitational-wave background using data from Advanced LIGO's first two observing runs, obtaining the most stringent upper limits to date on strength of the stochastic background. Finally, I consider how one might validate an apparent detection of the gravitational-wave background, confidently distinguishing a true astrophysical signal from spurious terrestrial artifacts.

The second part of this thesis concerns the search for electromagnetic counterparts to gravitational-wave events. The binary neutron star merger GW170817 was accompanied by a rich set of electromagnetic counterparts spanning nearly the entire electromagnetic spectrum. Beyond these counterparts, compact binaries may additionally generate powerful radio transients at or near their time of merger. First, I consider whether there is a plausible connection between this so-called "prompt radio emission" and fast radio bursts — enigmatic radio transients of unknown origin. Next, I present the first direct search for prompt radio emission from a compact binary merger using the Owens Valley Radio Observatory Long Wavelength Array (OVRO-LWA). While no plausible candidates are identified, this effort successfully demonstrates the prompt radio follow-up of a gravitational-wave source, providing a blueprint for LIGO and Virgo follow-up in their O3 observing run and beyond.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:LIGO gravitation
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Astrophysics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Weinstein, Alan Jay (advisor)
  • Hallinan, Gregg W. (co-advisor)
Thesis Committee:
  • Golwala, Sunil (chair)
  • Weinstein, Alan Jay
  • Hallinan, Gregg W.
  • Teukolsky, Saul A.
Defense Date:19 August 2019
Non-Caltech Author Email:thomas.a.callister (AT)
Record Number:CaltechTHESIS:05262020-184547015
Persistent URL:
Related URLs:
URLURL TypeDescription adapted for Ch. 10. adapted for Ch. 6. adapted for Ch. 9. adapted for Ch. 7. of article adapted for Ch. 6. adapted for Ch. 5. published work, not discussed in thesis. adapted for Ch. 4. adapted for Ch. 9.
Callister, Thomas Alfred, III0000-0001-9892-177X
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:13724
Deposited By: Thomas Callister
Deposited On:01 Jun 2020 22:12
Last Modified:26 Oct 2021 18:01

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