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3. SURVEYS AT HIGH REDSHIFT

The Deep Extragalactic Evolutionary Probe (DEEP) is a two-phase survey of galaxies at redshifts out to z ~ 1 using the Keck Telescopes and HST. [Koo] reported results from the first phase of DEEP, now approaching completion, and outlined plans for the more ambitious second phase, which will use the DEIMOS spectrograph on Keck. The first phase (Koo 1998) utilised LRIS on Keck, in conjunction with HST imaging, to carry out a redshift survey of ~ 1000 galaxies down to I = 24. This survey was followed up with more detailed studies of galaxy kinematics and other physical properties for small subsamples. The second phase, using the multi-slit spectrograph DEIMOS, aims to perform a redshift survey of 50,000 galaxies to I = 23 plus another 5000 galaxies going one magnitude deeper (Davis & Faber 1998). The sample will be defined using photometric redshifts to select the objects with 0.7 < z < 1.2. The main goals of the survey will be to study the evolution of both the galaxy population and the large-scale structure, and it is expected to run from early 2000 to late 2003.

More ambitious still is the VIRMOS survey described by [Guzzo]. This will use the optical (VIMOS) and near-infrared (NIRMOS) multi-slit spectrographs currently being built for ESO's VLT. Using 120 nights of guaranteed time on the VLT, the survey will measure redshifts for 100,000 galaxies down to IAB = 22 over 20 sq.deg, and for 50,000 galaxies down to IAB = 24 over 2 sq.deg (LeFevre et al. 1999). A further ~ 1000 redshifts will be obtained down to IAB ~ 26 over a 1 sq.arcmin field using the spectrograph's 6400-fibre integral field unit. VIMOS will see first light in mid-2000 and NIRMOS in mid-2001; the survey is expected to take 3-4 years.