Simultaneous observations of giant pulses from the crab pulsar, with the Murchison Widefield Array and Parkes radio telescope: Implications for the giant pulse emission mechanism

Journal Article · Mon Aug 10 04:00:00 EDT 2015 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/809/1/51· OSTI ID:22882803

Oronsaye, S. I.; Ord, S. M.; Bhat, N. D. R.; Tremblay, S. E.; McSweeney, S. J.; Tingay, S. J. ^[1]; Straten, W. van; Jameson, A.; Mitchell, D. A. ^[2]; Bernardi, G. ^[3]; Bowman, J. D. ^[4]; Briggs, F. ^[5]; Cappallo, R. J.; Lonsdale, C. J.; McWhirter, S. R. ^[6]; Deshpande, A. A. ^[7]; Greenhill, L. J. ^[8]; Hazelton, B. J. ^[9]; Johnston-Hollitt, M. ^[10]; Kaplan, D. L. ^[11] ; others, and

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1. International Centre for Radio Astronomy Research (ICRAR), Curtin University, Bentley, WA 6102 (Australia)
2. ARC Centre of Excellence for All-sky Astrophysics (CAASTRO), Sydney (Australia)
3. Square Kilometre Array South Africa (SKASA), 3rd Floor, The Park, Park Road, Pinelands, 7405 (South Africa)
4. School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States)
5. Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611 (Australia)
6. MIT Haystack Observatory, Westford, MA 01886 (United States)
7. Raman Research Institute, Bangalore 560080 (India)
8. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)
9. Department of Physics, University of Washington, Seattle, WA 98195 (United States)
10. School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6140 (New Zealand)
11. Department of Physics, University of Wisconsin–Milwaukee, Milwaukee, WI 53201 (United States)

We report on observations of giant pulses from the Crab pulsar performed simultaneously with the Parkes radio telescope and the incoherent combination of the Murchison Widefield Array (MWA) antenna tiles. The observations were performed over a duration of approximately one hour at a center frequency of 1382 MHz with 340 MHz bandwidth at Parkes, and at a center frequency of 193 MHz with 15 MHz bandwidth at the MWA. Our analysis has led to the detection of 55 giant pulses at the MWA and 2075 at Parkes above a threshold of 3.5σ and 6.5σ, respectively. We detected 51% of the MWA giant pulses at the Parkes radio telescope, with spectral indices in the range of −3.6>α>−4.9 (S{sub ν}∝ν{sup α}). We present a Monte Carlo analysis supporting the conjecture that the giant pulse emission in the Crab is intrinsically broadband, the less than 100% correlation being due to the relative sensitivities of the two instruments and the width of the spectral index distribution. Our observations are consistent with the hypothesis that the spectral index of giant pulses is drawn from normal distribution of standard deviation 0.6, but with a mean that displays an evolution with frequency from −3.00 at 1382 MHz, to −2.85 at 192 MHz.

• OSTI ID: 22882803
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 809; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United Kingdom
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
DETECTION
DISTRIBUTION
EMISSION
HYPOTHESIS
MONTE CARLO METHOD
PULSARS
RADIO TELESCOPES
RECREATIONAL AREAS
SCATTERING
SENSITIVITY