Detection of a Glitch in the Pulsar J1709−4429

Abstract

Pulsar glitches are thought to result from either quakes in the neutron star crust (Baym et al. 1969), or by a transfer of angular momentum between the superfluid interior and the outer crust (Anderson & Itoh 1975). The event manifests as a sudden increase in the observed spin period and spin-down of the pulsar, which can be followed by a recovery phase where the period exponentially returns to its pre-glitch evolution. We report here the detection of a glitch event in the pulsar J1709−4429 (also known as B1706−44) during regular monitoring observations with the Molonglo Observatory Synthesis Telescope (MOST). MOST is an aperture synthesis radio telescope located 40 km East of Canberra, Australia, operating in the 820–850 MHz frequency range. The UTMOST backend upgrade to the MOST (Bailes et al. 2017) has enabled study of the dynamic radio sky on millisecond timescales, and is well suited to pulsar timing, pulsar searches, observing single pulses from pulsars and discoveries of Fast Radio Bursts (FRBs) (Caleb et al. 2017; Farah et al. 2018). The glitch was found during timing operations, in which we regularly observe over 400 pulsars with up to daily cadence, while commensally searching for Rotating Radio Transients, pulsars, and FRBs.