Identifications and Spectroscopy of High-Redshift Radio Galaxies from the B3VLA Survey
Session 109 -- Extragalactic Radio Sources, Jets
Display presentation, Thursday, 12, 1995, 9:20am - 6:30pm

## [109.01] Identifications and Spectroscopy of High-Redshift Radio Galaxies from the B3VLA Survey

L. Maxfield, S.G. Djorgovski, D. Thompson, J.D. Smith (Caltech), M. Vigotti, G. Grueff (IR/CNR, Bologna)

We present new optical identifications of steep-spectrum radio sources from the B3 VLA survey (Vigotti et al. 1989, AJ 98, 419). Our subsample is limited by the spectral index ($-0.8 > \alpha_{408} > -1.3$), small angular size ($\leq 20$ arcsec), and flux ($S_{408} \geq 0.8$ Jy), and is expected to contain a large fraction of extremely distant galaxies. The IDs have been obtained at the Palomar 60-inch and 200-inch telescopes, and the spectra at the Palomar 200-inch and the Keck 10-m telescopes. The purpose of this investigation is to form a sample of moderate-power radio galaxies at cosmologically interesting redshifts, for the studies of galaxy evolution and radio source counts. We probe the flux range ($\sim 0.1 - 1$ Jy) where the deviations of source counts from the euclidean geometry are the largest, and we expect to see sources out to cosmological distances. Other scientific goals of this survey include the comparisons of galaxies with a wide range of radio power at similar redshifts (e.g., B3 vs. 3CR), a search for extremely distant clusters of galaxies, steep-spectrum quasars, and other unusual types of objects. We will present new, faint optical IDs for some 20 sources, and spectroscopy and redshifts for most of them, including several galaxies at $z > 2$.