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TOPIC: Parkes radio telescope


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RE: Parkes radio telescope
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Title: Improving the precision of pulsar timing through polarisation statistics
Authors: Stefan Osowski, Willem van Straten, Paul Demorest, Matthew Bailes

At the highest levels of pulsar timing precision achieved to date, experiments are limited by noise intrinsic to the pulsar. This stochastic wideband impulse modulated self-noise (SWIMS) limits pulsar timing precision by randomly biasing the measured times of arrival and thus increasing the root mean square (rms) timing residual. We discuss an improved methodology of removing this bias in the measured times of arrival by including information about polarised radiation. Observations of J0437-4715 made over a one-week interval at the Parkes Observatory are used to demonstrate a nearly 40 per cent improvement in the rms timing residual with this extended analysis. In this way, based on the observations over a 64 MHz bandwidth centred at 1341 MHz with integrations over 16.78 s we achieve a 476 ns rms timing residual. In the absence of systematic error, these results lead to a predicted rms timing residual of 30 ns in one hour integrations; however the data are currently limited by variable Faraday rotation in the Earth's ionosphere. The improvement demonstrated in this work provides an opportunity to increase the sensitivity in various pulsar timing experiments, for example pulsar timing arrays that pursue the detection of the stochastic background of gravitational waves. The fractional improvement is highly dependent on the properties of the pulse profile and the stochastic wideband impulse modulated self-noise of the pulsar in question.

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CSIRO's Parkes radio telescope was officially opened on 31 October 1961.



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Title: The Parkes Pulsar Timing Array Project
Authors: R. N. Manchester (1), G. Hobbs (1), M. Bailes (2), W. A. Coles (3), W. van Straten (2), M. J. Keith (1), R. M. Shannon (1), N. D. R. Bhat (2 and 4), A. Brown (1), S. G. Burke-Spolaor (5 and 1), D. J. Champion (6 and 1), A. Chaudhary (1), R. T. Edwards (7), G. Hampson (1), A. W. Hotan (1 and 2), A. Jameson (2), F. A. Jenet (8), M. J. Kesteven (1), J. Khoo (1), J. Kocz (2 and 9), K. Maciesiak (10), S. Oslowski (2 and 1), V. Ravi (11 and 1), J. R. Reynolds (1), J. M. Sarkissian (1), J. P. W. Verbiest (6 and 2), Z. L. Wen (12), W. E. Wilson (1), D. Yardley (13 and 1), W. M. Yan (14), X. P. You (15) ((1) CSIRO Astronomy and Space Science, Epping NSW, Australia, (2) Swinburne University of Technology, Hawthorn Vic, Australia, (3) University of California at San Diego, San Diego CA, USA, (4) Curtin University, Bentley WA, Australia, (5) Jet Propulsion Laboratory, California Institute of Technology, Pasadena CA, USA, (6) Max Planck Institut fur Radio Astronomie, Bonn, Germany, (7) 10 James Street, Whittlesea Vic, Australia, (8) University of Texas at Brownsville, Brownsville TX, USA, (9) Harvard-Smithsonian Center for Astrophysics, Cambridge MA, USA, (10) University of Zielona Gora, Zielona Gora, Poland, (11) University of Melbourne, Vic, Australia, (12) National Astronomical Observatories, CAS, Beijing, China, (13) University of Sydney, NSW, Australia, (14) Xinjiang Astronomical Observatory, CAS, Urumqi, China, (15) Southwest University, Chongqing, China)

A "pulsar timing array" (PTA), in which observations of a large sample of pulsars spread across the celestial sphere are combined, allows investigation of "global" phenomena such as a background of gravitational waves or instabilities in atomic timescales that produce correlated timing residuals in the pulsars of the array. The Parkes Pulsar Timing Array (PPTA) is an implementation of the PTA concept based on observations with the Parkes 64-m radio telescope. A sample of 20 millisecond pulsars is being observed at three radio-frequency bands, 50cm (~700 MHz), 20cm (~1400 MHz) and 10cm (~3100 MHz), with observations at intervals of 2 - 3 weeks. Regular observations commenced in early 2005. This paper describes the systems used for the PPTA observations and data processing, including calibration and timing analysis. The strategy behind the choice of pulsars, observing parameters and analysis methods is discussed. Results are presented for PPTA data in the three bands taken between 2005 March and 2011 March. For ten of the 20 pulsars, rms timing residuals are less than 1 microsec for the best band after fitting for pulse frequency and its first time derivative. Significant "red" timing noise is detected in about half of the sample. We discuss the implications of these results on future projects including the International Pulsar Timing Array (IPTA) and a PTA based on the Square Kilometre Array. We also present an "extended PPTA" data set that combines PPTA data with earlier Parkes timing data for these pulsars.

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Title: Fifty Years in Fifteen Minutes: The Impact of the Parkes Observatory
Authors: Philip Edwards

The scientific output of Parkes over its fifty year history is briefly reviewed on a year-by-year basis, and placed in context with other national and international events of the time.

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Title: The First Observations with the GRT at Parkes
Authors: R. M. Price

In this contribution Marcus Price gives a first hand account of some of the very first scientific observations undertaken with the "Giant Radio Telescope" at Parkes. It was clearly a very exciting time of discovery, enabled by superb engineering.

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Title: An Australian Icon - Planning and Construction of the Parkes Telescope
Authors: Peter Robertson

By almost any measure, the Parkes Radio Telescope is the most successful scientific instrument ever built in Australia. The telescope is unsurpassed in terms of the number of astronomers, both national and international, who have used the instrument, the number of research papers that have flowed from their research, and the sheer longevity of its operation (now over fifty years). The original planners and builders could not have envisaged that the telescope would have such an extraordinarily long and productive future. From the start, it was an international project by CSIRO that in the 1950s launched Australia into the world of `big science'. Partly funded by the US Carnegie and Rockefeller foundations, it was designed in England by Freeman Fox & Partners, and built by the German firm MAN. This article will give an overview of the origins of the idea for the telescope and the funding, planning and construction of the Parkes dish over the period 1954 to 1961.

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Title: Dishing up the Data: A Decade of Space Missions
Authors: John Sarkissian

The past decade has seen Parkes once again involved in a wide range of space tracking activities that have added to its illustrious legacy. This contribution is a personal recollection of those tracking efforts - both real and celluloid. We begin in a light-hearted vein with some behind-the-scenes views of the popular film, "The DISH", and then turn to more serious contributions; discussing the vital role of the telescope in alleviating the great "traffic jam" at Mars in 2003/04 and salvaging the Doppler Wind Experiment as the Huygens probe descended though the atmosphere of Saturn's largest moon, Titan, in mid-decade. We cap off the decade with a discussion of the search for the missing Apollo 11 slow-scan TV tapes.

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Title: Early Parkes Observations of Planets and Cosmic Radio Sources
Authors: K. I. Kellermann

We discuss early Parkes observations of the radio emission from the planets Mercury, Venus, Mars, Saturn, and Uranus. The sensitive Parkes 11 cm system was used to detect a surprisingly high observed nighttime temperature on Mercury, the first, but unrecognised, hint that the Mercury actually rotates with respect to the Sun, as well as detecting the faint radio emission from Uranus. We also discuss the anomalous spectrum of PKS 1934-63, the first recognised GPS source.

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Title: Pulsars at Parkes
Authors: R. N. Manchester

The first pulsar observations were made at Parkes on March 8, 1968, just 13 days after the publication of the discovery paper by Hewish and Bell. Since then, Parkes has become the world's most successful pulsar search machine, discovering nearly two thirds of the known pulsars, among them many highly significant objects. It has also led the world in pulsar polarisation and timing studies. In this talk I will review the highlights of pulsar work at Parkes from those 1968 observations to about 2006 when the Parkes Multibeam Pulsar Survey was essentially completed and the Parkes Pulsar Timing Array project was established.

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Title: The Parkes Pulsar Timing Array: What we've done and what we're doing
Authors: G. Hobbs

First observations for the Parkes Pulsar Timing Array project were carried out in February 2004. The project is ongoing and we currently observe approximately every three weeks. The data have led to numerous scientific results on topics as diverse as the solar wind, gravitational waves, measuring the masses of planetary systems in our solar system, atomic time scales, the interstellar medium and the pulsar emission mechanism. In this paper we provide an historical overview of the project and highlight the major discoveries.

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