Maps of the Cosmos ASP Conference Series, Vol. 216, 2005 M. Colless, L. Staveley-Smith, R. Stathakis First Science Results from the DEIMOS /DEEP2 Redshift Survey David C. Koo for the DEEP Team UC/Observatories/Lick Observatory & Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA, USA Abstract. DEEP2 is a major new Keck spectroscopic survey of 50,000 galax- ies that aims to provide a detailed map of the cosmos at redshift z rv 1. We present an overview of DEEP2 and its relation to DEEP and its predecessor (DEEPl) in terms of science goals, of the instrument DEIMOS that enables completion of this survey in only a few years, and of the current status of the project. First science projects that use the first 10% of the survey data and their early results are highlighted. 1. "What is DEEP, DEEP1, DEEP2, & DEIMOS? DEEP (Deep Extragalactic Evolutionary Probe) was initiated over 10 years ago to be a major spectral survey of faint field galaxies using the Keck 10-m Telescopes. The use of DElMaS (DEep Imaging Multi-Object Spectrograph) naturally divides DEEP into two parts (see Table 1). The first (DEEP1) is com- prised of a suite of pilot surveys of 10's to 100's of galaxies using pre-DElMaS spectrographs on Keck I and II. DEEP1 was designed to determine the technical feasibility and scientific scope of the second phase (DEEP2) of the DEEP pro- gram that will rely on using DElMaS. DEEP1 covered fields with HST WFPC2 images, which provide not only morphology and photometry but also structure, size, and inclination data needed to convert kinematics from Keck spectra into direct measures of dynamical mass. DEEP2 with DElMaS is distinguished from prior redshift surveys, includ- ing DEEP1, by its large sample size of over 50,000 galaxies, depth to RAB f'V 24, and high quality of the spectral data (see Table 1). To increase the efficiency of gathering redshifts at z f'V 1, three of the four 1HS fields will have a photometric pre-selection of galaxies, using BRI two-color diagrams, to isolate those most likely to have redshifts in the range of z > 0.7. The EGS field, with only half the area of the other three, will not have such a pre-selection, so that lower redshifts will be included to better support the large suite of complementary, deep surveys at other wavelengths. The only competitive survey currently un- derway is the VMOS-VLT Deep Survey (see article on VVDS by Le Fevre in these proceedings), which is aiming for a larger but generally brighter sample, has no redshift pre-selection, and is generally of lower spectral resolution. Large numbers for faint galaxy surveys are critical because galaxy evolu- tion involves a complex interplay of diverse galaxy classes, galaxy properties, environments, and physical mechanisms. Another reason is that cosmological constraints via the volume test (e.g., Newman & Davis 2002) or velocity func- 353 available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0074180900196780 Downloaded from https://www.cambridge.org/core. IP address: 54.83.158.191, on 12 Nov 2021 at 10:47:41, subject to the Cambridge Core terms of use,