The AURORA Survey

Authors

• Ali Ahmad Khostovan, University of KentuckyFollow
• Ryan L. Sanders, University of KentuckyFollow
• Alice E. Shapley, University of California, Los Angeles
• Michael W. Topping, University of Arizona
• Naveen A. Reddy, University of California Riverside
• Alex M. Garcia, University of Virginia
• Danielle A. Berg, University of Texas at Austin
• Leonardo Clarke, University of California, Los Angeles
• Fergus Cullen, University of Edinburgh
• Richard S. Ellis, University College London
• N. M.Förster Schreiber, Max Planck Institute for Extraterrestrial Physics
• Karl Glazebrook, Swinburne University of Technology
• Tucker Jones, University of California Davis
• Derek J. McLeod, University of Edinburgh
• Anthony J. Pahl, Carnegie Institution of Washington
• Max Pettini, Institute of Astronomy
• Paul Torrey, University of Virginia

Abstract

We present new constraints on the mass–metallicity (MZR) and fundamental metallicity relations (FMR) using a sample of 34 galaxies at 1.38 ≤ z ≤ 3.5 (median z = 2.28). These galaxies have direct T_e measurements from [O iii]4363 Å and/or [O ii]7320,7331 Å auroral emission lines detected with JWST/NIRSpec as part of the AURORA survey. The detection of both oxygen auroral lines allows for dual-zone direct T_e measurements and expands the dynamic range in (Formula presented) 12+log(O/H)  (7.68–8.65 dex), stellar mass (10⁸–10^10.4 M_⊙), and star formation rate (1–100 M_⊙ yr⁻¹) compared to previous direct T_e studies of the high-redshift MZR and FMR. We characterize the z ∼ 2 MZR and find a slope of 0.27 ± 0.04 and normalization of (Formula presented) 12+log(O/H)=8.44±0.04 at10¹⁰ M_⊙ with an intrinsic scatter of 0.10 dex, consistent with past strong-line MZR measurements. Comparisons with z ∼ 2 predictions from six simulations reveal that none reproduce our observed MZR normalization evolution between z ∼ 0 and z ∼ 2. This discrepancy suggests current models do not fully capture the chemical enrichment and feedback processes occurring at cosmic noon. However, all 34 galaxies are on or above the star-forming main sequence such that our sample may be biased toward lower (Formula presented) 12+log(O/H)  if the FMR persists at z ∼ 2. Correcting for this selection effect would increase O/H by ≈0.1 dex at 10^9.3 M_⊙ (the median mass of our sample), bringing our MZR into better agreement with that of IllustrisTNG. Lastly, we find our z ∼ 2.3 sample is consistent with the z ∼ 0 FMR within 0.1 dex in O/H, indicating that the smooth secular mechanisms regulating chemical enrichment, star formation, stellar mass, and outflows were in place at cosmic noon.

Document Type

Article

Publication Date

6-1-2026

Notes/Citation Information

Publisher Copyright: © 2026. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the https://creativecommons.org/licenses/by/4.0/. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

Digital Object Identifier (DOI)

10.3847/2041-8213/ae63d2

Archival?

Archival

Repository Citation

Khostovan, Ali Ahmad; Sanders, Ryan L.; Shapley, Alice E.; Topping, Michael W.; Reddy, Naveen A.; Garcia, Alex M.; Berg, Danielle A.; Clarke, Leonardo; Cullen, Fergus; Ellis, Richard S.; Schreiber, N. M.Förster; Glazebrook, Karl; Jones, Tucker; McLeod, Derek J.; Pahl, Anthony J.; Pettini, Max; and Torrey, Paul, "The AURORA Survey" (2026). Physics and Astronomy Faculty Publications. 772.
https://uknowledge.uky.edu/physastron_facpub/772