My research

Neutron stars are amongst the most fascinating and exotic objects in the Universe and I am interested in all manner of their phenomena. My research however, focuses on neutron stars as radio pulsars. Radio pulsars are the most stable rotators in the known Universe, rivalling the precision of atomic clocks.

Artist's impression of a neutron star

In many cases these celestial clocks are distinctly irregular over long timescales, exhibiting a phenomenon known as “timing noise”. In my research I work to understand the underlying processes driving timing noise. In younger pulsars, timing noise is dominated by recovery from glitch events in which the pulsar suddenly increases its rotation rate. In older pulsars, a slower, more gradual form of timing noise occurs which is a least partially attributable to the pulsar undergoing magnetospheric switching.

As well as rotational variability, pulsars also exhibit variability in their radio emission properties and these two phenomena have been shown to be correlated in some pulsars.

My work is both observational (using data from our radio telescopes at Jodrell Bank) and theoretical (in which I write computer models of pulsar phenomena). I have also written software that evaluates the timing behaviour of over 800 pulsars whenever they are observed by our telescopes.


Previously…

I completed my Masters degree in Astrophysics at the University of York. My research there focused on the nuclear physics of accreting neutron stars. These are binary systems in which a neutron star strips material from the envelope of a close evolved companion star. Under the high temperature and pressure conditions of a neutron star surface the material undergoes nuclear burning, getting hotter and hotter, until it explodes as a Type I X-ray burst.

Schematic of the rp-process

During these bursts, unstable proton rich nuclear species are formed in the rapid proton capture (rp- ) process. These decay on a range of timescales towards more stable species. Some species take a relatively long time to decay (e.g., Germanium-64, Selenium-68, Krypton-72) and so the abundances of these nuclei temporarily spike after a burst. These are known as waiting points and their decay rates are not well constrained. We investigated how sensitive the burst output is to the uncertainties in these decay rates and to the composition of the ashes from the previous burst.

I worked as part of the NuGrid collaboration under the supervision of Dr Alison Laird.


Publications

ORCID iD iconorcid.org/0000-0002-9581-2452


Conferences

  • Science Possibilities Investigating Neutron Stars (SPINS) – University of East Anglia, UK (2018)
    Talk title: The largest glitch in the Crab pulsar
  • PHAROS WG2 – Superfluids and superconductors in neutron stars – N. Copernicus Astronomical Center, Warsaw, Poland (2018)
    Talk title: The largest glitch in the Crab pulsar
  • LGBT STEMinar – University of York (2018) – Contributing Speaker
    Talk title: Pulsar timing and fundamental physics
  • Pulsar Astrophysics: The Next 50 years. Jodrell Bank (2017) – Contributing Speaker
    Talk title: Correlated emission and spin-variability in pulsars
  • NewCompStar. Southampton, UK (2016) – Invited Speaker
    Talk title: Resolving glitches in the Square Kilometre Array era
  • European Pulsar Timing Array. Cagliari, Sardinia (2016)
  • European Pulsar Timing Array. Orlean, France (2016)
  • International Pulsar Timing Array. New South Wales, Australia (2015)
  • European Pulsar Timing Array. Bonn, Germany (2015)
  • IoP Radioactivity in Astrophysics Meeting. University of York (2014)
  • Nucleosynthesis – Origins and Impacts. Royal Astronomical Society, London (2014)