DEEP2 Galaxy Redshift Survey


Data Release 4

Description of Observations

DEEP2 utilized the DEIMOS multi-object spectrograph on the Keck II 10-m telescope to observe a total of 411 slitmasks from 2002 - 2008, covering approximately 3 square degrees over 4 separate fields. As detailed in Newman et al. (2013), targets were selected from the BRI optical catalogs of Coil et al. (2004), reaching a limiting magnitude of RAB = 24.1. The 1200 line/mm grating was employed with a central wavelength of 7800Å, yielding a resolution of R ~ 5000 and typically covering a wavelength range of 6500Å - 9100Å (depending on slit placement on the mask). The OG550 order-blocking filter was used to limit flux blueward of 5550Å, and each slitmask was observed for approximately one hour, depending on the observing conditions (i.e., transparency and/or seeing). Typical slitlengths are ~6”, with a standard 1” slitwidth.

The DEIMOS data were reduced using the DEEP2 DEIMOS spec2d pipeline (Cooper et al. 2012), yielding sky-subtracted 1-d and 2-d spectra for each object. Redshifts were then measured using the DEEP2 Redshift Pipeline, with each redshift inspected by eye and assigned a quality code.

A summary of the DEIMOS slitmask observations along with information regarding the mask design details are presented via the following links:

                Summary of Slitmask Observations

                Slitmask Design Paramaters

In addition, DR4 includes information detailing the 2-d spatial selection function (or “window function”) for DEEP2. A more complete description of the selection function and general survey parameters is provided in Newman et al. (2013), with the 2-d selection function data accessible here.