A sample of southern Compact Steep Spectrum radio sources: The VLBI observations^*

¹ ATNF – CSIRO, Epping, Australia
² University of Tasmania, Hobart, Tasmania, Australia
³ COSSA/EOC – CSIRO, Canberra, Australia
⁴ Netherlands Foundation for Research in Astronomy, Postbus 2, 7990 AA, Dwingeloo, The Netherlands
⁵ Istituto di Radioastronomia – CNR, via Gobetti 101, 40129 Bologna, Italy
⁶ Astronomy Dept. Università di Bologna, via Ranzani 1, 40127 Bologna, Italy
⁷ Department of Physics, University of Sheffield, UK
⁸ Physics Dept. Università di Bologna, via Irnerio 46, 40126 Bologna, Italy
⁹ Jet Propulsion Laboratory, Caltech, Pasadena, CA, USA
¹⁰ University of Adelaide, Adelaide, SA, Australia
¹¹ ISAS, Sagamihara, Kanagawa, Japan
¹² University of Western Sydney, Kingswood, NSW, Australia

A. Tzioumis

Received: 25 April 2002
Accepted: 26 June 2002

Abstract

A small sample of 7 southern Compact Steep Spectrum (CSS) radio sources has been selected as part of the study of a larger flux-limited complete sample of radio sources. High resolution images, using the VLBI network in the southern hemisphere and the high resolution MERLIN array, are presented for all sources in the CSS sample. The overall morphology of each source consists of well-defined double lobes but with substantial diffuse and extended components present. In the majority of cases only a fraction of the total flux density is detected on the VLBI baselines, indicating the presence of larger extended radio structures. However, all sources are unresolved at arcsecond scales and are of sub-galactic size, with linear size in the range 0.1–2 kpc. The radio properties of the sources agree well with CSS sources in other samples.