The Parkes Pulsar Timing Array (PPTA) project is a combined effort from astronomers across several institutions in which pulsars are observed using the Murriyang Parkes Radio Telescope, which is located near the town of Parkes in New South Wales, Australia. By monitoring such pulsars over many years it is possible to search for ultra-low-frequency gravitational waves, to develop pulsar-based time standards and to improve our understanding of solar system dynamics.
The PPTA project was formed in 2004 and is the longest-running pulsar timing array project. The PPTA is a member of the International Pulsar Timing Array (IPTA), a global consortium in which we collaborate on pulsar timing array research. More details are available here about pulsars and the Murriyang Parkes radio telescope.
Results
A list of the PPTA publications can be obtained from the Astrophysics Data System (ADS). A few papers are highlighted below:
- Search for gravitational waves: In this paper we describe our search for a background of nanohertz-frequency gravitational waves. We show the data are consistent with the background at approximately the 2sigma level.
- The PPTA data releases: The PPTA has recently created its third data release. The data set will be publicly available from the CSIRO Data Archive and contains observations of 32 puslars with typical data spans of 18 years (with some increasing to 30 years with early observations). Our paper describes the creation of the data set, how to access the data set and the advantanges and challenges of using an ultra-wide-bandwidth receiver.
- Millisecond pulsar noise analysis: We have analysed the noise present in the data sets for our millisecond pulsars in Reardon, Zic et al. (2023) using data from the PPTA third data release.
- Wide-band timing of the Parkes Pulsar Timing Array UWL Data (2023): In this paper we presented the analysis of 3 years of PPTA data observed with our wide-band receiver system. This allowed us to obtain simultaneous measurements of pulse arrival times and dispersion measures.
- Constraining ultralight vector dark matter with the Parkes Pulsar Timing Array second data release (2022): In this paper we used the second data release of the Parkes Pulsar Timing Array project to constrain the local dark matter density.
- Evaluating the prevalence of spurious correlations in pulsar timing array data sets (2022): Here we explored how often false detections could be made in pulsar timing array studies.
We also note some exciting results from our IPTA partners. We are currently coordinating the publication of our most up-to-date data sets and our searches for the gravitational wave background. The IPTA has produced a checklist describing a formal process that will be followed to ensure PTA claims of detection are credible. The checklist is available from here.
About us
The PPTA team consists of astronomers around the World and contains experts in pulsars, gravitational waves, theoretical astrophysics, radio telescopes, software development and data analysis. The team currently consists of members from CSIRO, Swinburne University of Technology, Monash University, Macquarie University, University of Warsaw, Curtin University, Beijing Normal University, Hunan Normal University, Western Sydney University, US Naval Research Laboratory, Guangzhou University, Manly Astrophysics and the Auckland University of Technology.
The chairs of the PPTA Steering Committee are Andrew Zic (CSIRO) and Daniel Reardon (Swinburne University of Technology), who can be contacted for further details. We are also linked to the ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav) and members of the Gravitational Wave International Committee (GWIC) and the International Pulsar Timing Array (IPTA).