The UTMOST pulsar timing programme I: Overview and first results

Abstract

We present an overview and the first results from a large-scale pulsar timing programme that is part of the UTMOST project at the refurbished Molonglo Observatory Synthesis Radio Telescope (MOST) near Canberra, Australia. We currently observe more than 400 mainly bright southern radio pulsars with up to daily cadences. For 205 (8 in binaries, 4 millisecond pulsars) we publish updated timing models, together with their flux densities, flux density variability, and pulse widths at 843 MHz, derived from observations spanning between 1.4 and 3 yr. In comparison with the ATNF pulsar catalogue, we improve the precision of the rotational and astrometric parameters for 123 pulsars, for 47 by at least an order of magnitude. The time spans between our measurements and those in the literature are up to 48 yr, which allows us to investigate their long-term spin-down history and to estimate proper motions for 60 pulsars, of which 24 are newly determined and most are major improvements. The results are consistent with interferometric measurements from the literature. A model with two Gaussian components centred at 139 and 463 km s −1 fits the transverse velocity distribution best. The pulse duty cycle distributions at 50 and 10 per cent maximum are best described by log-normal distributions with medians of 2.3 and 4.4 per cent, respectively. We discuss two pulsars that exhibit spin-down rate changes and drifting subpulses. Finally, we describe the autonomous observing system and the dynamic scheduler that has increased the observing efficiency by a factor of 2-3 in comparison with static scheduling.

A nearby recent supernova that ejected the runaway star ζ Oph, the pulsar PSR B1706−16, and 60Fe found on Earth

“…While we used the proper motion of PSR B1706-16 from Fomalont et al (1997) ζ Oph B1706−16 UCL 2nd derivative of the frequency, 0.9 ± 0.2 · 10 −24 s −3 , e.g. due to glitches (Jankowski et al 2019 Zou et al (2005) show (their figure 2) that in particular the right ascension and, hence, proper motion in declination have strong uncertainties for such short epoch differences. We therefore consider the Fomalont et al (1997) proper motion the most reliable.…”

Autocorrelations in pulsar glitch waiting times and sizes

“…Large-scale, multi-object radio timing campaigns devoted to systematic searches for pulsar glitches are currently carried out at the Jodrell Bank (Espinoza et al 2011) and Parkes (Yu et al 2013;Yu & Liu 2017) Observatories. These campaigns are supplemented by additional current programs such as CHIME (Ng 2018) and UTMOST (Jankowski et al 2019) that take place at the Dominion Radio Astrophysical Observatory and Molonglo Synthesis Telescope respectively. The analysis in this paper combines the above observations with historical data sets from the Hartebeesthoek Radio Astronomy Observatory (Buchner & Flanagan 2008), Mount Pleasant Radio Observatory (Palfreyman et al 2016), Arecibo Observatory (Arzoumanian et al 2018), and Jet Propulsion Laboratory (Downs 1981).…”

The UTMOST pulsar timing programme – II. Timing noise across the pulsar population

“…ishnan et al 2020). As part of the timing programme, updated rotational models for 205 pulsars were published in the first paper of this series (Jankowski et al 2019) and 9 pulsar glitches have been reported so far (Jankowski et al 2015a(Jankowski et al ,b, 2016(Jankowski et al , 2017Lower et al 2018Lower et al , 2019.…”