Grant: Discovery Grants Program - Individual

Radio pulsars are neutron stars, the compact objects left behind after the supernova explosions of massive stars. Such a star has a mass about one and a half times that of our Sun but a diameter of only about 20 km, and it can spin anywhere from once every few seconds to more than 700 times per second. A pulsar appears to us as a kind of lighthouse, producing beams of radio waves which result in ""pulses"" as they sweep past our radio telescopes on Earth. One of the main goals of this research program is to track several of the fastest-spinning pulsars with the Arecibo and Green Bank (GBT) telescopes in order to look for or constrain tiny timing irregularities that might appear in common for pulsars close to each other on the sky, indicating the passage of gravitational waves with oscillation frequencies of years. This is a challenging project to be done with collaborators around the world. The data from this major project will also be used to explore the masses in as many pulsar binary systems as possible, trying to shed light on the differences in binary evolution properties in different types of systems. Relativistic systems, typically with two neutron stars in a close orbit, allow stringent tests of Einstein's theory of relativity in the potentially special regime near very compact objects. The research will pursue such tests via observations of the double pulsar and other relativistic systems. The research program also incorporates searches for pulsars at Arecibo and the GBT, to identify new pulsars to use to look for gravitational waves, to build up statistics to better understand the populations of both young and fast-spinning pulsars, and to find entirely new types of pulsars, including unexpected types of binaries. Finally, the program will look to the future, enabling work on pulsar search and timing modes on the upcoming Australian Square Kilometre Array Pathfinder telescope and looking ahead to pulsar science with the planned ultra-sensitive Square Kilometre Array.