Sigrid de Koff

Hubble Space TelescopeSnapshot Survey of 3CR Radio Source Counterparts. II. Radio Galaxies withz> 0.5

We present and describe optical counterparts to 46 3CR radio galaxies of redshifts less than 0.1 that were imaged with the Hubble Space Telescopes (HST) WFPC2 camera through the broadband F702W filter as part of the 3CR Snapshot Survey. This is the fifth and last such paper describing the 252 radio galaxies of this R-band survey. At the 01 resolution of the images, a wealth of detail is visible. Approximately 89% of the galaxies are ellipticals, and nearly all reside in groups or clusters of galaxies of various richness and compactness. Nearby elliptical companions of slightly smaller size and mass are common. Dust is prevalent in the cores of the 3C hosts; nearly half of the galaxies possess some type of dust structure, such as irregular dust lanes, filaments, or disks. Besides the well-known dust disks of 3C 264 and 3C 270, we have found five new candidates in 3C 31, 3C 40, 3C 296, 3C 449, and 3C 465, as well as in the central regions of the nearby neighbors of 3C 31 and 3C 465. Our sample includes six confirmed optical synchrotron jets in 3C 15, 3C 66B, 3C 78, 3C 264, 3C 274, and 3C 371, or approximately 13% of the sample. Unresolved nuclei, consistent with the point spread function of WFPC2, are found in 43%-54% of the galaxies and in the majority of galaxies with dust disks and optical jets.

New Optical Fields and Candidates of 10 3C Radio Sources. I. The R-Band Images*

Using new R-band images acquired as part of the 3CR Snapshot Survey with the Wide Field Planetary Camera 2 on the Hubble Space Telescope, we present positive optical identifications of three previously unidentified 3C radio sources (3C 91, 134, and 141). The fields of five others (3C 131, 152, 399.1, 415.2, and 468.1) are also presented with tentative identifications for some. The fields of two other sources (3C 249 and 3C 250) are empty. Eight sources lie along the Galactic plane (|b| < 10°) and are consequently heavily obscured, while the two empty fields are located at higher Galactic latitudes. Observed and corrected R magnitudes of each candidate are calculated. Confirmation of the true optical counterpart will require deep near-IR imaging and long-slit spectroscopy to determine the nature and redshift of the counterparts and candidates.