Please use this identifier to cite or link to this item:
http://hdl.handle.net/20.500.12386/25133
Title: | 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 | Authors: | Oronsaye, S. I. Ord, S. M. Bhat, N. D. R. Tremblay, S. E. McSweeney, S. J. Tingay, S. J. van Straten, W. Jameson, A. BERNARDI, GIANNI Bowman, J. D. Briggs, F. Cappallo, R. J. Deshpande, A. A. Greenhill, L. J. Hazelton, B. J. Johnston-Hollitt, M. Kaplan, D. L. Lonsdale, C. J. McWhirter, S. R. Mitchell, D. A. Morales, M. F. Morgan, E. Oberoi, D. Prabu, T. Udaya Shankar, N. Srivani, K. S. Subrahmanyan, R. Wayth, R. B. Webster, R. L. Williams, A. Williams, C. L. |
Issue Date: | 2015 | Journal: | THE ASTROPHYSICAL JOURNAL | Number: | 809 | Issue: | 1 | First Page: | 51 | Abstract: | 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\gt α \gt -4.9 ({S}<SUB>ν </SUB>\propto {ν }<SUP>α </SUP>). 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. | Acknowledgments: | We would like to thank Haydon Knight for useful contributions during the preparation of this paper. This scientific work makes use of the Murchison Radio-astronomy Observatory, operated by CSIRO. We acknowledge the Wajarri Yamatji people as the traditional owners of the Observatory site. Support for the MWA comes from the U.S. National Science Foundation (grants AST-0457585, PHY-0835713, CAREER-0847753, and AST-0908884), the Australian Research Council (LIEF grants LE0775621 and LE0882938), the U.S. Air Force Office of Scientific Research (grant FA9550-0510247), and the Centre for All-sky Astrophysics (an Australian Research Council Centre of Excellence funded by grant CE110001020). Support is also provided by the Smithsonian Astrophysical Observatory, the MIT School of Science, the Raman Research Institute, the Australian National University, and the Victoria University of Wellington (via grant MED-E1799 from the New Zealand Ministry of Economic Development and an IBM Shared University Research Grant). The Australian Federal government provides additional support via the Commonwealth Scientific and Industrial Research Organisation (CSIRO), National Collaborative Research Infrastructure Strategy, Education Investment Fund, and the Australia India Strategic Research Fund, and Astronomy Australia Limited, under contract to Curtin University. We acknowledge the iVEC Petabyte Data Store, the Initiative in Innovative Computing and the CUDA Center for Excellence sponsored by NVIDIA at Harvard University, and the International Centre for Radio Astronomy Research (ICRAR), a Joint Venture of Curtin University and The University of Western Australia, funded by the Western Australian State government. This research was conducted by the Australian Research Council Centre of Excellence for All-sky Astrophysics (CAASTRO), through project number CE110001020. | URI: | http://hdl.handle.net/20.500.12386/25133 | URL: | https://iopscience.iop.org/article/10.1088/0004-637X/809/1/51 | ISSN: | 0004-637X | DOI: | 10.1088/0004-637X/809/1/51 | Bibcode ADS: | 2015ApJ...809...51O | Fulltext: | open |
Appears in Collections: | 1.01 Articoli in rivista |
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