28/05/15 The UTMOST project passed a new milestone as the tied-array beam — which makes full use of the power of the MOST array — was applied to pulsar timing during April 2015. We were able to measure Times-of-Arrival of the pulses for over 30 pulsars in a day. Our timing to date had been restricted to the transit of pulsars across the meridian (when the telescope is pointing directly upwards) but during April 2015 software improvements allowed us to do this anywhere on the sky.
The image shows the pulsars timed in this way. The most up-to-date list can be found here. Each image shows the pulse at the bottom, and its dependence on the integration time. dispersion measure and frequency. The times of arrivals allow us to measure the changing rotation rate of the pulsar, including occasional “glitches“.
All these pulsars are timed individually, one at a time, but software upgrades currently being implemented will allow us to time as many pulsars as are visible in the large primary beam (8 square degrees) of the telescope. This will lead to huge improvements in the number of pulsars we can time, as our “30 pulsars in a day” campaign was dominated by slew times around the sky, rather than actual time spent observing pulsars. There is substantial room for efficiency improvements in the near future.
Image Credit: Chris Flynn, Fabian Jankowski and the UTMOST team