A SEARCH FOR PRIMEVAL GALAXIES AT Z = 1.9

We report on the first search for primeval galaxies at redshifts lower than 2. An area of 0.1 deg2 has been searched for emission-line objects at 3500 A; none has been found down to a 2 σ surface brightness threshold of 5.4 × 10-17 ergs cm-2 s-1 arcsec-2, corresponding to a surface brightness μu ≃ 27.6 mag arcsec-2 (for a pure emission-line source). For objects with structure similar to that of the z = 1.8 emission-line galaxy 3C 326.1, the limiting flux is somewhat brighter: ∼7 × 10-16 ergs cm-2 s-1, or ≈ 0.1/3C 326.1. From this limit, constraints have been placed on the formation of galaxies at redshifts 1.8 or greater. The resultant constraints are marginally in conflict with models for the formation of galaxies in universes dominated by cold dark matter.