Pulsars – rapidly-rotating, highly-magnetized neutron stars – make nature’s premier laboratories for advancing fundamental physics and astrophysics, with applications including testing strong-field gravity and probing physics at nuclear densities. More than 2500 pulsars are now known, and a vast majority of them were found in major sky surveys using large single-dish telescopes such as Parkes. Historically, pulsar surveys are proven to be highly rewarding, with a multitude of science enabled by the discoveries of exotic objects and specialised targets; e.g. relativistic binaries, millisecond pulsars and magnetars. Not so surprisingly, fundamental physics with pulsars is a headline science theme for the Square Kilometre Array (SKA), and conducting a full census of the Galactic pulsar population is among its key science drivers.
Finding pulsars with SKA precursor and pathfinder telescopes however pose numerous major challenges. The computational costs associated with beamforming and signal processing are prohibitive, besides the complexity associated in achieving the full potential in terms of exploiting their field of view or sensitivity. The Murchison Widefield Array (MWA) – a low-frequency (80-300 MHz) telescope in Western Australia, and the Precursor for SKA-LOW (i.e. the low-frequency component of the SKA) – has been no exception. Fortunately, with a major upgrade planned to expand the MWA, it will soon become possible to conduct sensitive pulsar searches with an efficiency that is ~2-3 orders magnitude better than that possible with any other currently operational facilities around the world.
This project will involve undertaking a large sky survey for pulsars with the MWA. Besides serving as an important SKA-demonstrator survey, it will also be the first major low-frequency southern sky pulsar survey since the 1990s. The project will involve developing new software and instrumentation, including efficient beam-forming techniques for pixelising the field of view, and localising pulsar discoveries rapidly using smart beam-forming and imaging techniques. Given the MWA’s unique access to the southern sky we expect a number of exciting discoveries, and consequently there is a lot of potential for high impact science.
Dr Steven Tremblay
Postdoctoral Fellow (CAASTRO)Read More