Weak gravitational lensing at radio wavelengths

• Main Author: Patel, Prina
• Other Authors: Bacon, David James ; Crittenden, Robert Glen ; Percival, William James
• Published: University of Portsmouth 2010
• Subjects: 520; Cosmology and Gravitation
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.538730

With the substantial improvement in instrumentation and our ability to now probe ever greater regions of space, the study of the Universe in its totality has moved towards the regime of a precision discipline. Several probes are now used by cosmologists to study the underlying cosmological model and understand its constituents. Modern cosmology has honed in on a concordance model that tells us that the Universe is predominantly composed of ‘dark’ components which still remain elusive to discovery. Weak lensing has emerged as one such powerful tool in probing the cosmological model. Its clean application of General Relativity, as well as its insensitivity in distinguishing between luminous and ‘dark matter' make it an attractive probe of the large scale structure in the Universe. To date, almost all weak lensing studies have been conducted using optical data. This is due primarily to the constraints required for a weak lensing study, i.e. high angular resolution and a high number density of distant sources, being most readily met at these wavelengths. The primary goal of this thesis is to address the feasibility of conducting such weak lensing experiments at the much longer, radio wavelengths. Many of the existing radio facilities are either undergoing (e.g. Extended Multi-Element Radio Linked Interferometer (eMERLIN1), Expanded Very Large Array (EVLA2)) or are scheduled to undergo major upgrades resulting in them being able to provide high resolution and high sensitivity data over a large field-of-view; aiding greatly in the detection of many more galaxies, a primary goal for weak lensing. Coupled with this, new, large interferometric arrays (e.g. Low Frequency Array (LOFAR3), and eventually the Square Kilometre Array (SKA4)) are in the process of being built and they too will provide the necessary quality of data for weak lensing experiments.