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Size of the Vela pulsar's emission region at 18 cm wavelength


Gwinn, CR and Johnson, MD and Reynolds, JE and Jauncey, DL and Tzioumis, AK and Hirabayashi, H and Kobayashi, H and Murata, Y and Edwards, PG and Dougherty, S and Carlson, B and Del Rizzo, D and Quick, JFH and Flanagan, CS and McCulloch, PM, Size of the Vela pulsar's emission region at 18 cm wavelength, Astrophysical Journal, 758, (1) Article 7. ISSN 0004-637X (2012) [Refereed Article]

Copyright Statement

Copyright 2012 The American Astronomical Society

DOI: doi:10.1088/0004-637X/758/1/7


We present measurements of the linear diameter of the emission region of the Vela pulsar at observing wavelength λ = 18 cm. We infer the diameter as a function of pulse phase from the distribution of visibility on the Mopra-Tidbinbilla baseline. As we demonstrate, in the presence of strong scintillation, finite size of the emission region produces a characteristic W-shaped signature in the projection of the visibility distribution onto the real axis. This modification involves heightened probability density near the mean amplitude, decreased probability to either side, and a return to the zero-size distribution beyond. We observe this signature with high statistical significance, as compared with the best-fitting zero-size model, in many regions of pulse phase. We find that the equivalent FWHM of the pulsar's emission region decreases from more than 400 km early in the pulse to near zero at the peak of the pulse and then increases again to approximately 800 km near the trailing edge. We discuss possible systematic effects and compare our work with previous results.

Item Details

Item Type:Refereed Article
Keywords:methods: statistical; pulsars: individual: Vela pulsar; radio continuum: stars; techniques: high angular resolution
Research Division:Physical Sciences
Research Group:Astronomical sciences
Research Field:Galactic astronomy
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the physical sciences
UTAS Author:McCulloch, PM (Professor Peter McCulloch)
ID Code:83126
Year Published:2012
Web of Science® Times Cited:8
Deposited By:Mathematics and Physics
Deposited On:2013-03-01
Last Modified:2017-11-03

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