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Issue A&A
Volume 454, Number 3, August II 2006
Page(s) 729 - 740
Section Extragalactic astronomy
DOI http://dx.doi.org/10.1051/0004-6361:20053885



A&A 454, 729-740 (2006)
DOI: 10.1051/0004-6361:20053885

European VLBI network observations of fourteen GHz-peaked-spectrum radio sources at 5 GHz

L. Xiang1, C. Reynolds2, R. G. Strom3 and D. Dallacasa4, 5

1  National Astronomical Observatories/Urumqi Observatory, CAS, 40-5 South Beijing Road, Urumqi 830011, PR China
    e-mail: liux@ms.xjb.ac.cn
2  Joint Institute for VLBI in Europe, Postbus 2, 7990 AA Dwingeloo, The Netherlands
    e-mail: reynolds@jive.nl
3  ASTRON, Postbus 2, 7990 AA Dwingeloo; and Astronomical Institute, University of Amsterdam, The Netherlands
    e-mail: strom@astron.nl
4  Dipartimento di Astronomia, Università di Bologna, via Ranzani 1, 40127 Bologna, Italy
    e-mail: daniele.dallacasa@unibo.it
5  Istituto di Radioastronomia - INAF, via P. Gobetti 101, 40129 Bologna, Italy

(Received 22 July 2005 / Accepted 15 March 2006)

Abstract
We present the results of EVN polarization observations of fourteen GHz-Peaked-Spectrum (GPS) radio sources at 5 GHz. These sources were selected from bright GPS source samples and we aimed at finding Compact Symmetric Objects (CSOs). We have obtained full polarization 5 GHz VLBI observations of 14 sources providing information on their source structure and spectral indices. The results show that two core-jet sources 1433-040 and DA193, out of 14 GPS sources, exhibit integrated fractional polarizations of 3.6% and 1.0% respectively. The other 12 sources have no clear detection of pc-scale polarization. The results confirm that the GPS sources generally have very low polarization at 5 GHz. The sources 1133+432, 1824+271 and 2121-014 are confirmed as CSOs. Three new CSOs 0914+114, 1518+046 and 2322-040 (tentative) have been classified on the basis of 5 GHz images and spectral indices. The sources 1333+589, 1751+278 and 2323+790 can be classified either as compact doubles, and then they are likely CSO candidates or core-jet sources; further observations are needed for an appropriate classification; 0554-026, 1433-040 and 1509+054 are core-jet sources. In addition, we estimate that a component in the jet of quasar DA193 has superluminal motion of $3.3\pm0.6\, h^{-1}\,c$ in 5.5 years.


Key words: galaxies: active -- quasars: general -- radio continuum: galaxies



© ESO 2006


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