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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 McCullochWe 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 JournalVolume
758Article number
7Number
7Pagination
1-19ISSN
0004-637XDepartment/School
School of Natural SciencesPublisher
IOP SciencePlace of publication
1427 E 60Th St, Chicago, USA, Il, 60637-2954Rights statement
Copyright 2012 The American Astronomical SocietyRepository Status
- Restricted