I'm an STFC funded postdoc in gravitational wave astronomy at the University of Glasgow. I'm a member of two research groups within the School of Physics and Astronomy - the Institute for Gravitational Research (IGR) and the Astronomy and Astrophysics group. If you ask nice and email me you can have a copy of my cv. My thesis is also available on request.

Gravitational Waves

For those that don't know what a gravitational wave is it can be described as a ripple in space-time. A gravitational wave's effect is to stretch and squeeze space as it propagates through it. Einstein's theory of general relativity predicts gravitational waves as a form of radiation that carries energy away from accelerating masses. To lose energy at any appreciable amount through gravitational radiation the objects must be some of the densest and most energetic systems in the universe, e.g. neutron stars and black holes.

As of yet gravitational waves have never been observed directly. There have, however, been measurments, originally those by Hulse and Taylor, of a binary pulsars whose orbits seems to be changing as if it were losing energy through gravitational waves. These provide some indirect evidence that gravitational waves are actually real, it also won Hulse and Taylor the 1993 Nobel Prize.

Over the past 30 years or so teams around the world have been working to directly detect gravitational waves. The efforts have taken so long because gravitational waves are so hard to detect and therefore the detectors need to be very sensitive. To illustrate this point the distortion caused by a gravitational wave is smaller than 1/10 the size of an atomic nucleus!

Very recently several detectors, based on the pricipal of laser interferometry, have been coming online, with the hope that these will be able to detect the strongest sources of waves. The detectors are the UK-German GEO600, the American LIGO, the French-Italian VIRGO, and the Japanese TAMA300. These detectors will also be used to test out better detector systems for future detectors.

Research

I am currently implementing a targeted search for gravitational waves from known pulsars. This search method uses an algorithm developed by Rejean Dupuis and Graham Woan, that looks for a known pulsar signal within the time domain data from the interferometers. It uses Bayesian statistics to determine probablity density functions for the unknown parameters of the pulsar. This search has so far been used to set upper limits on gravitational wave amplitude from a range of young and millisecond pulsars (see publications below).

My work also involves searching for gravitational wave ring-down signals from neutron star vibrational modes. These could be set up when a neutron star undergoes a glitch, is formed, or undergoes some other catastrophic crust reconfiguration (as might be the case for giant flares in SGRs).

Publications

1. Beating the spin-down limit on gravitational wave emission from the Vela pulsar, J. Abadie et al. (The LIGO Scientific Collaboration and the Virgo Collaboration), Ap. J., 737, 93, (2011), arXiv:1104.2712.
2. Prospects of observing continuous gravitational waves from known pulsars, M. Pitkin, MNRAS, 415, 2, 1849-1863 (2011), arXiv:1103.5867.
3. Gravitational Wave Detection by Interferometry (Ground and Space), M. Pitkin, S. Reid, S. Rowan and J. Hough, Living Rev. Relativity, 14, 5, (2011), arXiv:1102.3355.
4. Searches for gravitational waves from known pulsars with S5 LIGO data, B. Abbott et al. (The LIGO Scientific Collaboration and The Virgo Collaboration), S. Bégin, A. Corongiu, N. D'Amico, P. C. C. Freire, J. W. T. Hessels, G. B. Hobbs, M. Kramer, A. G. Lyne, R. N. Manchester, F. E. Marshall, J. Middleditch, A. Possenti, S. M. Ransom, I. H. Stairs and B. Stappers, Ap. J., 713, 671-685 (2010), arXiv:0909.3583.
5. Beating the spin-down limit on gravitational wave emission from the Crab pulsar, B. Abbott et al. (The LIGO Scientific Collaboration), Ap. J. Lett., 683, L45-L49 (2008), arXiv:0805.4758.
6. An Evidence Based Search For Gravitational Waves From Neutron Star Ring-downs, J. Clark, I. S. Heng, M. Pitkin and G. Woan, Phys. Rev. D, 76, 043003 (2007), gr-qc/0703138.
7. Upper limits on gravitational wave emission from 78 radio pulsars, B. Abbott et al. (The LIGO Scientific Collaboration), M. Kramer and A. G. Lyne, Phys. Rev. D, 76, 042001 (2007), gr-qc/0702039.
8. Binary system delays and timing noise in searches for gravitational waves from known pulsars, Matthew Pitkin and Graham Woan, Phys. Rev. D, 76, 042006 (2007), gr-qc/0703152.
9. Limits on gravitational wave emission from selected pulsars using LIGO data, B. Abbott et al. (The LIGO Scientific Collaboration), M. Kramer and A. G. Lyne, Phys . Rev. Lett., 94, 181103 (2005), NASA ADS, gr-qc/0410007.

1. Is there potential complementarity between LISA and pulsar timing?, M. Pitkin, J. Clark, M. A. Hendry, I. S. Heng, C. Messenger, J. Toher and G. Woan, Journal of Physics: Conference Series, 122, 012004 (2008), arXiv:0802.2460.
2. Searching for gravitational waves from known pulsars, Matthew Pitkin for the LIGO Scientific Collaboration, Class. Quant. Grav., 22, 18, pp.S1277-S1282 (2005), NASA ADS, gr-qc/0505076.
3. Searching for gravitational waves from the Crab pulsar - the problem of timing noise, Matthew Pitkin and Graham Woan, Class. Quant. Grav., 21, 5, pp.S843-S846 (2004), NASA ADS, gr-qc/0312057 or IoP.

Other Publications

1. Feature: Making waves, Nexus News, June 2004 (unedited version here).

Research related travel and presentation links

Public talks

• Gravitational wave astronomy - observing the fabric of space-time
  • Airdrie Public Obsevatory, 24/10/03.
  • DACE Dark Energy school, 29/11/03.
  • Stirling Astronomical Society, 9/12/05.
  • Renfrewshire Astronomical Society, 14/12/06.
  • DACE Extreme Astrophysics, 5/02/07.
  • DACE Life in the Cosmos, 20/02/07.

Undergraduate Project - Jovian Aurorae

In the fourth year of my ndergraduate degree at UCL I produced a research project. The project I chose involved determining the three parameters of temperature, column density and total emission of the ionosphere of Jupiter in it's auroral regions. These parameters were calculated using certain infrared emission lines from the moleclar ion H₃⁺. Correlations between the three parameters were looked at to study the process involved in energy transport in the Jovian ionosphere. My supervisors for this project were Dr Tom Stallard and Dr Steve Miller, in UCLs Atmospheric Physics Laboratory. During the project I had to use the programming languages FORTRAN and IDL. If you are interested in this area you can view my project by clicking here.