The AURORA Survey

Authors

• Anthony J. Pahl, Carnegie Institution of Washington
• Alice Shapley, University of California, Los Angeles
• Naveen A. Reddy, University of California Riverside
• Ryan Sanders, University of KentuckyFollow
• Michael W. Topping, University of Arizona
• Danielle A. Berg, University of Texas at Austin
• Callum T. Donnan, NSF's National Optical-Infrared Astronomy Research Laboratory
• James S. Dunlop, University of Edinburgh
• Richard S. Ellis, University College London
• N. M. Förster Schreiber, Max Planck Institute for Extraterrestrial Physics
• K. Glazebrook, Swinburne University of Technology
• Derek J. McLeod, University of Edinburgh
• Max Pettini, Institute of Astronomy
• Daniel Schaerer, University of Geneva

Abstract

We present ionizing photon production efficiencies (ξ_ion) for 63 z = 1.5–6.9 star-forming galaxies using precise nebular dust attenuation corrections from the JWST Assembly of Ultradeep Rest-optical Observations Revealing Astrophysics (AURORA) survey. A subset of objects within AURORA have individually determined nebular dust attenuation curves, which vary significantly in shape and normalization, resulting in reduced systematic uncertainty when constraining the total attenuation of Hα luminosity, and thus the intrinsic ionizing output within our sample. We find evidence for positive correlations between ξ_ion and redshift, equivalent width of [O iii] λ5007, and O32 = [O iii] λ5007/[O ii] λλ3726, 3729, and negative correlations between ξ_ion and stellar attenuation, UV luminosity (L_UV), stellar mass, and direct-method metallicity. We test alternate dust prescriptions within this sample, and find that the total attenuation is lower when using the commonly assumed Galactic extinction curve or when assuming that stellar attenuation is equal to nebular attenuation. We also find that assuming either of these alternate dust prescriptions can change the slope of the relationships between ξ_ion and galaxy property, notably inducing a flat trend between ξ_ion and L_UV within AURORA. While the novel nebular dust curves derived from AURORA spectroscopy reveal obscured ionizing photon production within star-forming galaxies at these redshifts, a more complete understanding of stellar attenuation is required to fully reduce the dust systematics on ξ_ion for inclusion in reionization models.

Document Type

Article

Publication Date

1-1-2026

Notes/Citation Information

Publisher Copyright: © 2025. The Author(s). Published by the American Astronomical Society.

Digital Object Identifier (DOI)

10.3847/1538-4357/ae1cab

Archival?

Archival

Repository Citation

Pahl, Anthony J.; Shapley, Alice; Reddy, Naveen A.; Sanders, Ryan; Topping, Michael W.; Berg, Danielle A.; Donnan, Callum T.; Dunlop, James S.; Ellis, Richard S.; Förster Schreiber, N. M.; Glazebrook, K.; McLeod, Derek J.; Pettini, Max; and Schaerer, Daniel, "The AURORA Survey" (2026). Physics and Astronomy Faculty Publications. 795.
https://uknowledge.uky.edu/physastron_facpub/795