VLA polarimetry of compact steep spectrum sources

¹ Istituto di Radioastronomia del CNR, Bologna, Italy
² Institute for Astrophysics, University of New Mexico, Albuquerque NM, U.S.A.
³ Dipartimento di Fisica, Universitá degli Studi, Bologna, Italy
⁴ Tata Institute of Fundamental Research, National Centre for Radio Astrophysics, Pune 411 007, India

Send offprint request to: F. Mantovani

Received: 24 December 1996
Accepted: 12 February 1997

Abstract

We present the polarization properties at sub-arcsecond resolutions of 8 Compact Steep-spectrum Sources (CSSs) observed with the VLA A-array at 5, 8.4 and 15 GHz. We find that the three most compact sources, two of which are unresolved and have an angular diameter milliarcsec are not polarized. Of the remaining 5, the two associated with quasars have prominent radio jets while the two galaxies and one unidentified object are dominated by their lobe emission. The components of these medium sized objects with median values of percentage polarization of about 9% at 5 GHz and 11% at 8.4 GHz, are more strongly polarized than the compact sources and do not show evidence of very large rotation measures.