Detection of crab giant pulses using the mileura widefield array low frequency demonstrator field prototype system

N. D.Ramesh Bhat, Randall B. Wayth, Haydon S. Knight, Judd D. Bowman, Divya Oberoi, David G. Barnes, Frank H. Briggs, Roger J. Cappallo, David Herne, Jonathon Kocz, Colin J. Lonsdale, Mervyn J. Lynch, Bruce Stansby, Jamie Stevens, Glen Torr, Rachel L. Webster, J. Stuart B Wyithe

Research output: Contribution to journalArticle

23 Scopus citations

Abstract

We report on the detection of giant pulses from the Crab Nebula pulsar at a frequency of 200 MHz using the field deployment system designed for the Mileura Widefield Array's Low Frequency Demonstrator (MWA-LFD). Our observations are among the first high-quality detections at such low frequencies. The measured pulse shapes are deconvolved for interstellar pulse broadening, yielding a pulse-broadening time of 670 ± 100 μs, and the implied strength of scattering (scattering measure) is the lowest that is estimated toward the Crab Nebula from observations made so far. The sensitivity of the system is largely dictated by the sky background, and our simple equipment is capable of detecting pulses that are brighter than ∼9 kJy in amplitude. The brightest giant pulse detected in our data has a peak amplitude of ∼50 kJy, and the implied brightness temperature is 1031.6 K. We discuss the giant pulse detection prospects with the full MWA-LFD system. With a sensitivity over 2 orders of magnitude larger than the prototype equipment, the full system will be capable of detecting such bright giant pulses out to a wide range of Galactic distances; from ∼ 15 to ∼30 kpc depending on the frequency. The MWA-LFD will thus be a highly promising instrument for the studies of giant pulses and other fast radio transients at low frequencies.

Original languageEnglish (US)
Pages (from-to)618-627
Number of pages10
JournalAstrophysical Journal
Volume665
Issue number1 PART 1
DOIs
StatePublished - Aug 10 2007
Externally publishedYes

Keywords

  • ISM: individual (Crab Nebula)
  • ISM: structure
  • Pulsars: general
  • Pulsars: individual (Crab pulsar)
  • Scattering

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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    Bhat, N. D. R., Wayth, R. B., Knight, H. S., Bowman, J. D., Oberoi, D., Barnes, D. G., Briggs, F. H., Cappallo, R. J., Herne, D., Kocz, J., Lonsdale, C. J., Lynch, M. J., Stansby, B., Stevens, J., Torr, G., Webster, R. L., & Stuart B Wyithe, J. (2007). Detection of crab giant pulses using the mileura widefield array low frequency demonstrator field prototype system. Astrophysical Journal, 665(1 PART 1), 618-627. https://doi.org/10.1086/519444