Variability in GPS Sources
journal contribution
posted on 2023-05-16, 19:41 authored by Jauncey, DL, King, EA, Bignall, HE, James LovellJames Lovell, Kedziora-Chudczer, L, Tzioumis, AK, Tingay, SJ, Macquart, JP, Peter McCullochPeter McCullochFlux 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. © Astronomical Society of Australia 2003.
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Publication title
Publications of the Astronomical Society of AustraliaVolume
20Pagination
151-155ISSN
1323-3580Department/School
School of Natural SciencesPublisher
CSIRO PublishingPlace of publication
Collingwood, AustraliaRepository Status
- Restricted
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