Astrophysics, abstract
astro-ph/0604605

From: Michael Kramer [view email]

Date: Fri, 28 Apr 2006 11:26:30 GMT (35kb)

A periodically active pulsar giving insight into magnetospheric physics

Authors: M. Kramer, A.G. Lyne, J.T. O'Brien, C.A. Jordan, D.R. Lorimer (Jodrell Bank Observatory, University of Manchester, Macclesfield, SK11 9DL, UK)

Comments: 12 pages, 2 figures

Journal-ref: Published in Science, 2006, Vol. 312, 549-551

PSR B1931+24 (J1933+2421) behaves as an ordinary isolated radio pulsar during active phases that are 5-10 days long. However, the radio emission switches off in less than 10 seconds and remains undetectable for the next 25-35 days, then it switches on again. This pattern repeats quasi-periodically. The origin of this behaviour is unclear. Even more remarkably, the pulsar rotation slows down 50% faster when it is on than when it is off. This indicates a massive increase in magnetospheric currents when the pulsar switches on, proving that pulsar wind plays a substantial role in pulsar spin-down. This allows us, for the first time, to estimate the currents in a pulsar magnetospheric during the occurrence of radio emission.

http://arxiv.org/abs/astro-ph/0604605