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Size of the Vela Pulsar's Radio Emission Region: 500 km

C. R. Gwinn·M. J. Ojeda·M. C. Britton·J. E. Reynolds·D. L. Jauncey·E. A. King·P. M. McCulloch·J. E. J. Lovell·C. S. Flanagan·D. P. Smits·R. A. Preston·D. L. Jones
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Abstract

We use interstellar scattering of the Vela pulsar to determine the size of its emission region. From interferometric phase variations on short baselines, we find that radio-wave scattering broadens the source by 3.4+/-0.3 milliarcseconds along the major axis at position angle 81+/-3 degrees. The ratio of minor axis to major axis is 0.51+/-0.03. Comparison of angular and temporal broadening indicates that the scattering material lies in the Vela-X supernova remnant surrounding the pulsar. From the modulation of the pulsar's scintillation on very short baselines, we infer a size of 500 km for the pulsar's emission region. We suggest that radio-wave refraction within the pulsar's magnetosphere may plausibly explain this size.

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C. R. Gwinn, M. J. Ojeda, M. C. Britton, J. E. Reynolds, D. L. Jauncey, E. A. King, P. M. McCulloch, J. E. J. Lovell, C. S. Flanagan, D. P. Smits, R. A. Preston, D. L. Jones. 1996-08-14. Size of the Vela Pulsar's Radio Emission Region: 500 km. https://doi.org/10.1086/310734

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