
TY  - JOUR
A1  - Jauncey, D. L. 
A1  - King, Edward A. 
A1  - Bignall, Hayley E. 
A1  - Lovell, J. E. J. 
A1  - Kedziora-Chudczer, Lucyna 
A1  - Tzioumis, A. K. 
A1  - Tingay, S. J. 
A1  - Macquart, Jean-Pierre 
A1  - McCulloch, P. M. 
T1  - Variability in GPS Sources
JF  - Publications of the Astronomical Society of Australia
JO  - Publ. Astron. Soc.  Aust.
Y1  - 2003
VL  - 20
IS  - 1
SP  - 151
EP  - 155
KW  - galaxies: active &#8212; quasars: general
UR  - https://doi.org/10.1071/AS03023 
N2  - 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, &#126;10&#37;, 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, &#x2265;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&#8211;273, which possesses strong and variable circular polarisation, and which exhibits IDV in all Stokes parameters. 
ER  -

