CLOCKS AND BURSTS · Searching for nature's best clocks and extragalactic millisecond transients with large interferometric arrays: from the GMRT to the SKA

Millisecond pulsars (MSPs) are rapidly rotating neutron stars that emit a beam of radio waves fromtheir magnetic poles. Their rate of rotation is very stable and so the pulses detected as they spin are likethe ticks of an extremely precise clock. Measuring small deviations in the rate that this clock runs makes themideal laboratories to test gravity theories and as detectors for gravitational waves. In addition to the regularradio emission from pulsars, millisecond transient bursts (FRBs) are observed at the locations of cataclysmicevents, making them useful probes for extreme states of gravity, pressure, temperature and magnetic fields.Their extragalactic origin makes them useful to study the poorly constrained baryon content of the intergalacticmedium. Motivated by the need to discover more of both these source classes and my recent discoveries of MSPsat the Giant Metrewave Radio Telescope (GMRT), the largest array in the world, combined with the expertise ofUniversity of Manchester in non-imaging high time resolution astronomy, we propose for the highly sensitiveGMRT High Resolution Southern Survey (GHRSS) for MSPs and transients. This survey is calculated to find atleast 45 MSPs and tens of FRBs. The simultaneous time domain search and imaging capability of this surveyalso provides an unique opportunity of discovery and simultaneous localisation of MSPs and FRBs, which iscurrently not employed at any other telescope. As the GMRT is a prototype for the global Square KilometreArray (SKA) and SKA1-mid in particular, the techniques we propose to develop here will be directly applicable.This project brings together my expertise in leading GMRT pulsar surveys with the extensive pulsar and transientsearch experience and SKA knowledge of my UK host. This combination will allow us to deliver cutting edgescience in collaboration with European scientists and enable us to play a leading role in the SKA.