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Periodic Changes in Intensity and Arrival Time of Pulses from the Vela Pulsar: Evidence for Free Precession?

Published online by Cambridge University Press:  12 April 2016

A.A. Deshpande  and
P.M. McCulloch
A.A. Deshpande
Affiliation:
Raman Research Institute, Bangalore 560080, India
P.M. McCulloch
Affiliation:
Physics Department, University of Tasmania, Box 252C, GPO Hobart, Tasmania 7001, Australia

Extract

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We present dual-frequency measurements on the Vela pulsar with a view to study the slow variations in the pulsed flux and the apparent differences in the pulse arrival times. We examine the data for correlated variations between the pulse intensities and arrival times at the two frequencies and discuss two main possibilities in order to explain the observed behaviour.

The data presented here consists of a) Pulse intensities, S635 & S950, at S635 & S950 MHz respectively and b) the ‘residual’ differences in the time of arrival of the pulse at the lower frequency, ΔTOA, with respect to that at the higher frequency. These data, over a span of ~1300 days (during 1988-92), were obtained as a part of the routine monitoring of the Vela pulsar from Mt. Pleasant Observatory of University of Tasmania, Hobart (see McCulloch et al. 1990).

Type
Part 2 Precision Measurements
Information
International Astronomical Union Colloquium , Volume 160: Pulsars: Problems and Progress , 1996 , pp. 101 - 102
Copyright
Copyright © Astronomical Society of the Pacific 1996

References

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