A medium-deep redshift survey of a minislice at the north Galactic pole

The first results from a new medium-deep redshift survey of galaxies in a 4° by 49′ slice close to the north Galactic pole have yielded 240 new redshifts, providing a total of 327 redshifts out of 814 galaxies visible to B = 20. This survey extends the transverse information for the first five peaks found in the redshift histogram from a deeper pencil beam sample reported by Broadhurst et al. The first peak, corresponding to the Great Wall, has a significant contribution from galaxies in the outer region of the Coma cluster. Another peak at z ≈ 0.125 is largely confined to a small area and would have been missed by the original deep cone survey if the position were shifted by only 1° westward. Only one of the structures we detect has a wall-like appearance. In general, the high-density structures have irregular shapes, and alternate with low-density regions or voids with various sizes up to ∼ 100 h^-1 Mpc, which is a pattern similar to that detected by the shallower wide-angle surveys.