Research

My research focuses on the studies of fast radio transients and pulsars. For a more technical view of what I get up to check out my research publications.

Fast Radio Transients

So what are they? Well, I sometimes sum up this aspect of my research by saying: "I look for explosions in space". To be more specific I search for any astrophysical sources which pulse, burst, flare or show variability in the radio sky. Why do I study the transient sky in radio (i.e not optical, X-ray or anything else)? Well, there are several reasons - this is where sources of non-thermal and in some cases coherent emission are to be found (i.e. exciting extreme physics is at play!), we can obtain very high time resolution, we are 'photon rich' (although we are in the regime where we must think of light as a wave not a photon!), we can observe from Earth, we can use technology to create MASSIVE telescopes (see below) on scales impossible with other wavelengths, and most importantly in the transient radio sky we have a large completely unexplored parameter space where we expect to find many sources*.

*that is not to mention the sources we don't know about yet - a colleague of mine once said that this work encompasses Rumsfeld Classes I, II and III :)

Pulsar Searches

I have been and continue to be involved in many successful searches for radio pulsars*. These include searching the Parkes Multi-beam Pulsar Survey many times, using supercomputing clusters with many thousands of processors, and with the help of volunteers from the general public via the Einstein@Home project. The procedures for identifying pulsar candidates in the vast rivers of data collected by radio telescopes are computationally difficult, and often require in depth data analysis and clever signal processing. The search is hindered by the presence of much stronger terrestrial signals (mobile phones, TV, radar, car ignitions, lightning, electric fences, aeroplanes, satellites, ...) which mask the pulsar signals. Once identified pulsar candidates must be re-observed for confirmation, and then observed regularly to study interesting physics (e.g. of their 'clock-like' behaviour, used to test General Relativity and as gravitational wave detectors, piecing together stellar evolution paths by studying interesting binary systems, constraining the Galactic supernova rate etc.).

* Pulsars are neutron stars - city-sized stars which are highly magnetised and which rotate very quickly - up to 1000 times per second (that's kitchen blender speed by the way!). They emit beams of radio emission from their poles which sweep across the Earth as the star spins, if the beams happen to be pointed towards us. If we point a radio telescope at these stars we then see a pulse every rotation.

Pulsar Variability Timescales

While it is true to say that there are pulsars which act as extremely accurate cosmic clocks, it is also true to say that there many pulsars which some variability on an extremely large range of timescales. Some of these behaviours are even (quasi-)periodic, and the origin of this variable and switching behaviour is mostly unexplained (so far).

The LOw Frequency ARray (LOFAR)

LOFAR is currently the most awesome telescope on planet Earth, which is primarily in the Netherlands but with constituent 'stations' also in the UK, France, Germany and Sweden. I am a member of the Pulsar Working Group, as part of the Transients Key Science Project for LOFAR. I will add some information about this here soon.

The Square Kilometre Array (SKA)

The SKA will be even more awesome, which will be built across Southern Africa and Australia. I will add some information about this here soon.