JWST's TEMPLATES for Star Formation: The First Resolved Gas-phase Metallicity Maps of Dust-obscured Star-forming Galaxies at z ∼ 4
Hutchison, Taylor A.; Mahler, Guillaume; Rigby, Jane R.; Cathey, Jared; Gonzalez, Anthony H.; Phadke, Kedar A.; Aravena, Manuel; Birkin, Jack E.; Hayward, Christopher C.; Kim, Keunho J.; Narayanan, Desika; Reuter, Cassie; Solimano, Manuel; Sulzenauer, Nikolaus; Vizgan, David; Bayliss, Matthew B.; Khullar, Gourav; Malkan, Matthew A.; Chapman, Scott C.; Welch, Brian; Spilker, Justin S.; Smith, J. D. T.; Weiss, Axel; Gururajan, Gayathri; Olivier, Grace M.; Vieira, Joaquin D.
United States, Chile, Canada, Italy, United Kingdom, Denmark, Germany
Abstract
We present the first spatially resolved maps of gas-phase metallicity for two dust-obscured star-forming galaxies at z ~ 4, from the JWST TEMPLATES Early Release Science program, derived from NIRSpec integral field unit spectroscopy of the Hα and [N II] emission lines. Empirical optical line calibrations are used to determine that the sources are globally enriched to near-solar levels. While one source shows elevated [N II]/Hα ratios and broad Hα emission consistent with the presence of an active galactic nucleus in a ≳1 kpc region, we argue that both systems have already undergone significant metal enrichment as a result of their extremely high star formation rates. Utilizing Atacama Large Millimeter/submillimeter Array rest-frame 380 μm continuum and [CI](3P2-3P1) line maps we compare the spatial variation of the metallicity and gas-to-dust ratio in the two galaxies, finding the two properties to be anticorrelated on highly resolved spatial scales, consistent with various literature studies of z ~ 0 galaxies. The data are indicative of the enormous potential of JWST to probe the enrichment of the interstellar medium on ~kpc scales in extremely dust-obscured systems at z ~ 4 and beyond.