Methods for optimising detection of strong gravitationally-lensed explosive transients

• Main Author: Ryczanowski, Dan
• Format: Dissertation
• Language: English
• Published: University of Birmingham 2022
• Subjects: QB Astronomy; QC Physics

Gravitational lensing is a cornerstone prediction of Einstein's General Theory of Relativity, which provided us with the first piece of direct evidence that led to his theory becoming the accepted interpretation of gravity. Now, over one hundred years later, the study of gravitational lensing has evolved into a diverse field that is continually utilised to unveil the wondrous subtleties of our universe. Specifically, the gravitational lensing of explosive transient sources is a field which is set to make major contributions to some of the biggest open debates in astrophysics -- including the Hubble Tension, the physics and nature of transient progenitors, the redshift evolution of explosive transient rates, and new tests of Einstein's theory. The next few years are pivotal for the subject, when observatories such as Rubin will transform studies of these events by increasing the number of discovered lensed transients by two orders of magnitude. In this thesis, I give a description of my original contributions to the field, which are focused around optimising the detection of gravitationally-lensed explosive transient sources such as supernovae, gamma-ray bursts, gravitational waves and kilonovae using a watchlist-based approach. The outcome of my research has led to a new understanding of how a lensed transient watchlist should be constructed, and the development of an algorithm that is capable of locating the galaxy clusters relevant to the lensing of such transients within existing all-sky survey data, which can then be used to populate a lensed transient watchlist. In addition, I describe the searches for lensed transient sources I have been active in alongside my research.