The coins sample: VLBA identifications of compact symmetric objects

We present results of multifrequency polarimetric VLBA observations of 34 c ompact radio sources. The observations are part of a large survey undertake n to identify compact symmetric objects (CSOs) observed in the northern sky (COINS). CSOs are of particular interest in the study of the physics and e volution of active galaxies. Based on VLBI continuum surveys of similar to 2000 compact radio sources, we have defined a sample of 52 CSOs and CSO can didates. In this paper we identify 18 previously known CSOs, and introduce 33 new CSO candidates. We present continuum images at several frequencies a nd, where possible, images of the polarized flux density and spectral index distributions for the 33 new candidates and one previously known but uncon firmed source. We find evidence to support the inclusion of 10 of these can didates into the class of CSOs. Thirteen candidates, including the previous ly unconfirmed source, have been ruled out. Eleven sources require further investigation. The addition of the 10 new confirmed CSOs increases the size of this class of objects by 50%.