Deep Spectroscopy in the Field of 3C 212

We present the results of long-slit and multiaperture spectroscopy of faint galaxies in the field of the z = 1.049 quasar 3C 212. We show that an apparently aligned optical feature beyond the northwest radio lobe has a redshift z = 0.928, and a similarly aligned feature just beyond the southeast radio lobe has a redshift z = 1.053, quite close to that of the quasar. While the northwest optical component is extremely well aligned with the radio jet and has a morphology that is very similar to that of the radio lobe lying 3 arcsec interior to it, the fact that we find three other field galaxies with closely similar redshifts indicates that it is most likely a member of an intervening group rather than an unusual example of true alignment with the radio structure. In addition, we have found two galaxies (besides the one near the southeast radio lobe) having redshifts close to that of 3C 212. We have firm or probable redshifts for 66 out of 82 galaxies we have observed in this field. Comparison with the redshift distribution of faint field galaxies indicates that a large fraction of the remaining 16 galaxies are likely to be at redshifts greater than about 1.4. There are at least two low-redshift dwarf starburst galaxies showing low metal abundance and high ionization in our sample; such galaxies are likely to be relatively common in very faint samples, and, under certain conditions, they could be confused with high-redshift objects. (Author)