The NIRSpec Wide GTO Survey

Abstract

The Near-infrared Spectrograph (NIRSpec) on the James Webb Space Telescope is uniquely suited to studying galaxies in the distant Universe with its combination of multi-object capabilities and sensitivity over a large range in wavelength (0.6 − 5.3 μm). Here we present the NIRSpec Wide survey, part of the NIRSpec Instrument Science Team’s Guaranteed Time Observations, using NIRSpec’s microshutter array to obtain spectra of more than 3200 galaxies at z >  1 at both low and high resolution (R ≈ 100 and 2700) for a total of 105 hours. With 31 pointings covering ≈320 arcmin2 across the five CANDELS fields with exquisite ancillary photometry from the Hubble Space Telescope, the NIRSpec Wide survey represents a fast and efficient way of probing galaxies in the early Universe. Pointing centers are determined to maximize the observability of the rarest, high-value sources. Subsequently, the microshutter configurations are optimized to observe the maximum number of “census” galaxies with a selection function based primarily on HST/F160W magnitude, photometric or slitless grism redshift, and predicted Hα flux tracing the bulk of the galaxy population at cosmic noon (zmed = 2.0). We present details on the survey strategy, the target selection, an outline of the motivating science cases, and discuss upcoming public data releases to the community.