The LDSS deep redshift survey

Abstract

The low dispersion survey spectrograph (LDSS) has been used to obtain intermediate dispersion spectrsocpy for a sample of 149 faint objects selected randomly from the magnitude range b(J) between 21 and 22.5. The results of the spectroscopic survey are presented. The form of the redshift distribution and the distribution of forbidden O II equivalent widths are discussed. It is found that the LDSS increased the limiting magnitude of field redshift surveys by about 1.0 mag, while maintaining a high degree of completeness. The redshift distribution closely matches that predicted by a no-evolution model based on local galaxy properties. Comparison with the no-evolution model shows a significant excess (40 percent) in the number of galaxies with O II forbidden 3727 A equivalent widths greater than 20 A, supporting the conclusion of Broadhurst et al. (1988) that there is increased star formation in low-luminosity galaxies at moderate redshifts. Also, The flat-spectrum galaxies and compact objects in the survey are discussed.