The COINS Sample: VLBA Identifications of Compact Symmetric Objects

Abstract

We present results of multifrequency polarimetric VLBA observations of 34 compact radio sources. The observations are part of a large survey undertaken to identify compact symmetric objects (CSOs) observed in the northern sky (COINS). CSOs are of particular interest in the study of the physics and evolution of active galaxies. Based on VLBI continuum surveys of D2000 compact radio sources, we have deÐned a sample of 52 CSOs and CSO candidates. In this paper we identify 18 previously known CSOs, and introduce 33 new CSO candidates. We present continuum images at several frequencies and, where possible, images of the polarized Ñux density and spectral index distributions for the 33 new candidates and one previously known but unconÐrmed source. We Ðnd evidence to support the inclusion of 10 of these candidates into the class of CSOs. Thirteen candidates, including the previously unconÐrmed source, have been ruled out. Eleven sources require further investigation. The addition of the 10 new conÐrmed CSOs increases the size of this class of objects by 50%.