Pulsar Timing

Jodrell Bank/ Lovell telescope (2032)

At Jodrell Bank, we have over 40 years of pulsar rotation history for over 900 pulsars providing a rich database for the long term study of timing behaviour. Pulsar Timing is one of the research topics of the Pulsar and Time Domain Astrophysics group.

  • European Pulsar Timing Array (EPTA)

    Lovell Telescope
    Lovell Telescope, Jodrell Bank Observatory

     The European Pulsar Timing Array is made up of scientists and engineers from over 20 institutions across Europe working in observations, instrumentation, data reduction, and theory. By using the 5 biggest radio telescopes in Europe (The 76-m Lovell in the UK, the 94-m equivalent WSRT in the Netherlands, the 100-m Effelsberg in Germany, the 64-m SRT in Sardinia, and the 94-m equivalent Nancay Radio Telescope in France), the EPTA is capable of observing at a wide range of frequencies with high cadence per source. 

    Gravitational waves are ripples in space-time, predicted by Einstein's theory of general relativity, which stretch and compress spacetime. As pulsars emit pulses with such amazing regularity, organisations such as the European Pulsar Timing Array can use pulsars as extremely accurate clocks, at distances of light years from the Earth. By comparing the measured pulse arrival times to the expected arrival times, the distortion of space caused by a passing gravitational wave should be detectable as a deviation from the timing model, correlated across all pulsars. Pulsar timing arrays are sensitive to extremely low-frequency gravitational radiation generated by supermassive black hole binaries, cosmic strings, and the inflationary era.

    While gravitational waves have not been directly detected, their effect is significant in relativistic binary systems, such as the Hulse-Taylor binary (1993 Nobel Prize), and the double pulsar PSR J0737-3039. These systems convert large amount of orbital energy to gravitational radiation, which reduces the orbital distance, and will eventually cause the objects to merge catalysmically.

    As well as confirming the prediction from general relativity, astronomers hope to be able to use gravitational waves to do astronomy. Astronomy generally only uses electromagnetic waves, which can be blocked by matter along the line of sight, and may not be emitted at all by black holes and dark matter. Gravitational wave astronomy on the other hand should allow us to observe the universe in an entirely new way.

    For EPTA information, please contact James Mckee.

  • The LEAP Project

    The locations of the LEAP/EPTA telescopes.
    The locations of the LEAP/EPTA telescopes.

    As a means of bridging the gap in sensitivity between the current generation of radio telescopes and the SKA [link to page], the European Pulsar Timing Array has found an innovative way to combine their existing telescopes into a fully-steerable virtual telescope, of 195-m equivalent dish size, known as LEAP: The Large European Array for Pulsars.

    LEAP is used for monthly observations of millisecond pulsars, where data is recorded simultaneously with The Lovell Telescope, the Effelsberg 100-m Radio Telescope, the Nancay Radio Telescope, the Westerbork Synthesis Radio Telescope, and the Sardinia Radio Telescope. The hard disks containing the observation data are shipped to Jodrell Bank Observatory, where they are put on a work cluster for processing.

    The main goal of LEAP is to achieve the high sensitivity required to make a direct gravitational wave detection, but the high sensitivity afforded by LEAP is useful for individual-pulsar science projects. Some projects to be completed in 2016 include a study of giant pulse emission from B1937+21, single-pulses from J1713+0747, and long observations of the galactic centre magnetar J1745-2900.

    For LEAP information, please contact James Mckee.

    Current LEAP Team:

    Cees Bassa (ASTRON, The Netherlands Intitute for Radio Astronomy)
    Gemma Janssen (ASTRON, The Netherlands Intitute for Radio Astronomy)
    Ramesh Karuppusamy (Max Planck Institute for Radio Astronomy)
    Michael Kramer (Max Planck Institute for Radio Astronomy)
    K.J. Lee (Kavli Institute for Astronomy and Astrophysics, Peking University)
    Kuo Liu (Max Planck Institute for Radio Astronomy)
    James McKee (Jodrell Bank Centre for Astrophysics, The University of Manchester)
    Delphine Perrodin (INAF - Osservatorio Astronomico di Cagliari)
    Mark Purver (Jodrell Bank Centre for Astrophysics, The University of Manchester)
    Sortirios Sanidas (Anton Pannekoek Institute for Astronomy, University of Amsterdam)
    Roy Smits (ASTRON, The Netherlands Intitute for Radio Astronomy)
    Benjamin Stappers (Jodrell Bank Centre for Astrophysics, The University of Manchester)
    Weiwei Zhu (Max Planck Institute for Radio Astronomy)

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