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Variable Sources at 408 MHz

Published online by Cambridge University Press:  25 April 2016

W. B. McAdam
W. B. McAdam*
Affiliation:
School of Physics, University of Sydney
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Extract

Flux density changes at low frequency in extragalactic sources were discovered in 1969 by Hunstead (1972a) and this low frequency variability has since been confirmed in the range 318 to 962 MHz at five other observatories. The changes are usually small and near the stability limit of most telescopes, but occasionally large changes ~ 30% are found. Many sources show changes at both low and high frequencies, but these appear uncorrelated even with delay lags of several years, and the likelihood of low frequency variability in a source cannot be predicted from high frequency behaviour. This paper reports statistics on the proportion of sources that showed changes of different amplitudes during a monitoring program with the Molonglo Cross in 1975/76.

Type
Contributions
Information
Publications of the Astronomical Society of Australia , Volume 4 , Issue 1 , 1980 , pp. 70 - 72
Copyright
Copyright © Astronomical Society of Australia 1980

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References

Fanti, R., Ficarra, A., Mantovani, F., and Padrielli, L., Astron. Astrophys. Suppl., 36, 359 (1979).Google Scholar
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