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

journal contribution
posted on 2023-05-17, 16:23 authored by Gwinn, CR, Johnson, MD, Reynolds, JE, Jauncey, DL, Tzioumis, AK, Hirabayashi, H, Kobayashi, H, Murata, Y, Edwards, PG, Dougherty, S, Carlson, B, Del Rizzo, D, Quick, JFH, Flanagan, CS, Peter McCullochPeter McCulloch
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.

History

Publication title

Astrophysical Journal

Volume

758

Article number

7

Number

7

Pagination

1-19

ISSN

0004-637X

Department/School

School of Natural Sciences

Publisher

IOP Science

Place of publication

1427 E 60Th St, Chicago, USA, Il, 60637-2954

Rights statement

Copyright 2012 The American Astronomical Society

Repository Status

  • Restricted

Socio-economic Objectives

Expanding knowledge in the physical sciences

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