Journal Article

Observations and modelling of pulsed radio emission from CU Virginis

K. K. Lo, J. D. Bray, G. Hobbs, T. Murphy, B. M. Gaensler, D. Melrose, V. Ravi, R. N. Manchester and M. J. Keith

in Monthly Notices of the Royal Astronomical Society

Published on behalf of The Royal Astronomical Society

Volume 421, issue 4, pages 3316-3324
Published in print April 2012 | ISSN: 0035-8711
Published online April 2012 | e-ISSN: 1365-2966 | DOI: http://dx.doi.org/10.1111/j.1365-2966.2012.20555.x
Observations and modelling of pulsed radio emission from CU Virginis

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We present 13 and 20 cm radio observations of the magnetic chemically peculiar star CU Virginis taken with the Australia Telescope Compact Array. We detect two circularly polarized radio pulses every rotation period which confirm previous detections. In the first pulse, the lower frequency emission arrives before the higher frequency emission and the ordering reverses in the second pulse. In order to explain the frequency dependence of the time between the two pulses, we construct a geometric model of the magnetosphere of CU Virginis, and consider various emission angles relative to the magnetic field lines. A simple electron cyclotron maser emission model, in which the emission is perpendicular to the magnetic field lines, is not consistent with our data. A model in which the emission is refracted through cold plasma in the magnetosphere is shown to have the correct pulse arrival time frequency dependence.

Keywords: magnetic fields; radiation mechanisms: non‐thermal; stars: individual: CU Virginis; stars: rotation; radio continuum: stars

Journal Article.  4970 words.  Illustrated.

Subjects: Astronomy and Astrophysics

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