Hostname: page-component-8448b6f56d-gtxcr Total loading time: 0 Render date: 2024-04-24T23:34:55.602Z Has data issue: false hasContentIssue false
  • English
  • Français

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
Get access Rights & Permissions [Opens in a new window]

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

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Fanti, R., Ficarra, A., Mantovani, F., and Padrielli, L., Astron. Astrophys. Suppl., 36, 359 (1979).Google Scholar
Hunstead, R. W., Astrophys. Lett., 12, 193 (1972a).Google Scholar
Hunstead, R. W., Mori Not. R. Astron. Soc., 157, 367 (1972b).CrossRefGoogle Scholar
Kesteven, M. J. L., Bridle, A. H., and Brandie, G. W., Astron. J., 81, 919 (1976).Google Scholar
McAdam, W. B., Proc. Astron. Soc. Aust., 3, 86 (1976).CrossRefGoogle Scholar
Wyllie, D. V., Mon. Not. R. Astron. Soc., 142, 229 (1969).Google Scholar