The NIRSpec Wide GTO Survey

¹ Department of Astronomy, University of Wisconsin-Madison, 475 N. Charter St., Madison, WI 53706, USA
² Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany
³ Leiden Observatory, Leiden University, PO Box 9513 2300 RA Leiden, The Netherlands
⁴ Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy
⁵ European Space Agency (ESA), European Space Astronomy Centre (ESAC), Camino Bajo del Castillo s/n, 28692 Villafranca del Castillo, Madrid, Spain
⁶ Centro de Astrobiología (CAB), CSIC–INTA, Cra. de Ajalvir Km. 4, 28850 Torrejón de Ardoz, Madrid, Spain
⁷ Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH, UK
⁸ Sorbonne Université, CNRS, UMR 7095, Institut d’Astrophysique de Paris, 98 bis bd Arago, 75014 Paris, France
⁹ European Southern Observatory, Karl-Schwarzschild-Strasse 2, 85748 Garching bei München, Germany
¹⁰ Kavli Institute for Cosmology, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK
¹¹ Cavendish Laboratory, University of Cambridge, 19 JJ Thomson Avenue, Cambridge CB3 0HE, UK
¹² AURA for European Space Agency (ESA), ESA Office, Space Telescope Science Institute, 3700 San Matin Drive, Baltimore, MD 21218, USA
¹³ Astrophysics Research Institute, Liverpool John Moores University, 146 Brownlow Hill, Liverpool L3 5RF, UK
¹⁴ NRC Herzberg, 5071 West Saanich Rd, Victoria, BC V9E 2E7, Canada

Received: 8 March 2024
Accepted: 21 May 2024

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 (z_med = 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.