Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/2740

Title

Variability in GPS sources

Author(s)

Bignall, Hayley E.;  Jauncey, David L.;  Kedziora-Chudczer, Lucyna L.;  King, Edward A.;  Lovell, James E.;  Macquart, Jean-Pierre;  Tingay, Steven J.;  Tzioumis, Anastasios K.;  McCulloch, Peter M.

Abstract

Flux density monitoring data at 2.3 and 8.4 GHz is presented for a sample of 33 southern hemisphere GPS sources, drawn from the 2.7 GHz Parkes survey. This monitoring data, together with VLBI monitoring data, shows that a small fraction of these sources, ~10%, vary. Their variability falls into several categories: sources whose spectral classification is, at best, ephemeral on a timescale of years; sources with a stable GPS classification that vary, but retain their classification; and a small number of sources that exhibit interstellar scintillation, but that maintain a mean GPS spectrum. Existing data on GPS sources with higher frequency peaks, ≥3 GHz, reveals that many such sources vary. However, the majority of these sources possess a GPS spectrum only during outbursts, and hence should perhaps be classified as ephemeral GPS sources. In addition, significant levels of circular polarisation have been found in a number of GPS sources, both amongst the variables and non-variables. Remarkable amongst these is PKS 1519–273, which possesses strong and variable circular polarisation, and which exhibits IDV in all Stokes parameters.

Publication type

Journal article

Source

Publications of the Astronomical Society of Australia, Vol. 20, no. 1 (2003), pp. 151-155(5)

Publication year

2003

Publisher

CSIRO Publishing

Format

pp. 151-155(5)

ISSN

1323-3580

Publisher URL

Publications of the Astronomical Society of Australia

Publisher URL

http://dx.doi.org/10.1071/AS03023

Copyright

© Astronomical Society of Australia 2003

Peer reviewed