Are wide-angle radio-tail QSOs members of clusters of galaxies. I. VLA maps at 20 cm of 117 radio quasars

We report snapshot VLA observations obtained in the A array at 1413 MHz for 117 strong radio sources associated with QSOs, most of which have z<1.5 and 3C, 4C, or Molonglo identifications. Data from the literature and our observations now provide structural information for all but 8 of the 263 QSOs in the Hewitt and Burbidge compilation which are 3C, 4C, MC2, or MC3 sources and which have z<1.5. Of the 255 objects in the resulting sample, 113 are triple sources with well-defined radio axes. An appreciable portion of these triple sources has slightly bent radio axes, but 19 objects have radio axes bent more than 200, and six of these have bending angles exceeding 400. If we assume that these larger distortions are caused by interaction with an intracluster medium, as is believed to be the case for wide-angle radio-tail galaxies, then at least 5%--17% of the quasars in our sample of triple radio sources are associated with clusters having intracluster medium (ICM) densities exceeding 10-3 particles/cm3. Perrenod's models of ICM evolution suggest that the percentage of sources showing distortions might decrease with increasing redshift. It is therefore interesting that all five sources with bending angles exceeding 500 have z<0.9.Several of the bent triples are boomerang shaped, with straight bridges connecting each outer component with the central source. On the other hand, a few of the distorted objects (e.g., 0232-042) show curved bridges connecting off-axis outer components with the central sources. Study of the relationship between bending angle and physical size demonstrates that all of the strongly bent sources (theta>200) have comparatively small physical sizes. We have also used data for 299 3C, 4C, MC2, and MC3 radio sources associated with quasars in the Hewitt-Burbidge catalog to re-examine the relationship between largest angular size (LAS) and redshift