In the near future, gravitational wave (GW) detections are expected to become common, opening a new window on the Universe. Using the two 4 km Laser Interferometer Gravitational wave Observatory (LIGO) detectors and the 3 km Virgo detector we can triangulate a passing GW to a region of the sky with an area of tens of square degrees. These regions can then be observed using electromagnetic (EM) observatories. Pairing GW and EM observations can verify the astrophysical origin of a GW detection, and provide a more complete picture of the processes taking place.
This thesis describes the first triggered search for EM counterparts to GW candidates from the 2009-2010 LIGO/Virgo observing run. To improve the search strategy of this observing run, we created a catalogue of galaxies within 100 Mpc, known as the Gravitational Wave Galaxy Catalogue (GWGC), which was used to select locations in the GW skymaps to be imaged by EM partner observatories. Analysis of optical images taken as part of this run, from the Liverpool Telescope (LT) and ROTSE observatory network, find no associated counterparts. We also simulate the optical transients expected from GW sources across the LIGO/Virgo horizon of 50 Mpc, and find that the LT would be able to detect most optical counterparts across the majority of the horizon distance, while ROTSE can only detect counterparts over a fraction of the same distance.
Finally, we present the design specifications of GOTO, a wide field-of-view observatory to image the skymaps expected to be produced by the next generation of GW detectors. This telescope will be able to cover ∼70 square degrees to a limiting magnitude of ∼21, the sky area and limiting magnitude required to offer a reasonable chance of detecting an EM counterpart. While NS-NS merger models are uncertain, a tentative first detection of a kilonova-like counterpart to GRB130603B leaves us optimistic that the advanced detector era will provide the first GW detections and EM counterparts.
