CSSs in a sample of B2 radio sources of intermediate strength

¹ National Centre for Radio Astrophysics, Tata Institute of Fundamental Research, Post Bag No. 3, Ganeshkhind, Pune 411 007, India,
² Jodrell Bank Observatory, University of Manchester, Macclesfield, Cheshire SK11 9DL, UK
³ Istituto di Radioastronomia, CNR, via P. Gobetti 101, Bologna, Italy
⁴ Arecibo Observatory, HC3 Box 53995, Arecibo, Puerto Rico PR 00612, USA
⁵ Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany

Corresponding author: D. J. Saikia, djs@ncra.tifr.res.in

Received: 12 March 2002
Accepted: 28 May 2002

Abstract

We present radio observations of 19 candidate compact steep-spectrum (CSS) objects selected from a well-defined, complete sample of 52 B2 radio sources of intermediate strength. These observations were made with the VLA A-array at 4.835 GHz. The radio structures of the entire sample are summarised and the brightness asymmetries within the compact sources are compared with those of the more extended ones, as well as with those in the 3CRR sample and the CSSs from the B3-VLA sample. About 25 per cent of the CSS sources exhibit large brightness asymmetries, with a flux density ratio for the opposing lobes of >5, possibly due to interaction of the jets with infalling material. The corresponding percentage for the larger-sized objects is only about 5 per cent. We also investigate a possible dependence of the flux density asymmetry of the lobes on redshift, since this might be affected by more interactions and mergers in the past. No such dependence is found. A few individual objects of interest are discussed in the paper.