TY - JOUR
T1 - The AURORA Survey
T2 - A New Era of Emission-line Diagrams with JWST/NIRSpec
AU - Shapley, Alice E.
AU - Sanders, Ryan L.
AU - Topping, Michael W.
AU - Reddy, Naveen A.
AU - Berg, Danielle A.
AU - Bouwens, Rychard J.
AU - Brammer, Gabriel
AU - Carnall, Adam C.
AU - Cullen, Fergus
AU - Davé, Romeel
AU - Dunlop, James S.
AU - Ellis, Richard S.
AU - Förster Schreiber, N. M.
AU - Furlanetto, Steven R.
AU - Glazebrook, Karl
AU - Illingworth, Garth D.
AU - Jones, Tucker
AU - Kriek, Mariska
AU - McLeod, Derek J.
AU - McLure, Ross J.
AU - Narayanan, Desika
AU - Oesch, Pascal
AU - Pahl, Anthony J.
AU - Pettini, Max
AU - Schaerer, Daniel
AU - Stark, Daniel P.
AU - Steidel, Charles C.
AU - Tang, Mengtao
AU - Clarke, Leonardo
AU - Donnan, Callum T.
AU - Kehoe, Emily
N1 - Publisher Copyright:
© 2025. The Author(s). Published by the American Astronomical Society.
PY - 2025/2/20
Y1 - 2025/2/20
N2 - We present results on the emission-line properties of z = 1.4-7.5 star-forming galaxies in the Assembly of Ultradeep Rest-optical Observations Revealing Astrophysics (AURORA) Cycle 1 JWST/NIRSpec program. Based on its depth, continuous wavelength coverage from 1 to 5 μm, and medium spectral resolution (R ∼ 1000), AURORA includes detections of a large suite of nebular emission lines spanning a broad range in rest-frame wavelength. We investigate the locations of AURORA galaxies in multiple different emission-line diagrams, including traditional BPT diagrams of [O iii]λ5007/Hβ versus [N ii]λ6583/Hα, [S ii]λλ6717, 6731/Hα, and [O i]λ6300/Hα, and the ionization-metallicity diagram of [O iii]λ5007/[O ii]λ3727 (O32) versus ([O iii]λ5007+[O ii]λ3727)/Hβ (R23). We also consider a bluer rest-frame ionization-metallicity diagram introduced recently to characterize z > 10 galaxies, [Ne iii]λ3869/[O ii]λ3727 versus ([Ne iii]λ3869+[O ii]λ3727)/Hδ, as well as longer-wavelength diagnostic diagrams extending into the rest-frame near-IR: [O iii]λ5007/Hβ versus [S iii]λλ9069, 9532/[S ii]λλ6717, 6731 (S32), and He iλ1.083 μm/Paγ and [S iii]λ9532/Paγ versus [Fe ii]λ1.257μm/Paβ. With a significant boost in signal-to-noise ratio and large, representative samples of individual galaxy detections, the AURORA emission-line diagrams presented here definitively confirm a physical picture in which chemically young, α-enhanced, massive stars photoionize the interstellar medium (ISM) in distant galaxies with a harder ionizing spectrum at fixed nebular metallicity than in their z ∼ 0 counterparts. We also uncover previously unseen evolution prior to z ∼ 2 in the [O iii]λ5007/Hβ versus [N ii]λ6583/Hα diagram, which motivates deep NIRSpec observations at even higher redshift. Finally, we present the first statistical sample of rest-frame near-IR emission-line diagnostics in star-forming galaxies at high redshift. In order to truly interpret rest-frame near-IR line ratios including [Fe ii]λ1.257 μm, we must obtain better constraints on dust depletion in the high-redshift ISM.
AB - We present results on the emission-line properties of z = 1.4-7.5 star-forming galaxies in the Assembly of Ultradeep Rest-optical Observations Revealing Astrophysics (AURORA) Cycle 1 JWST/NIRSpec program. Based on its depth, continuous wavelength coverage from 1 to 5 μm, and medium spectral resolution (R ∼ 1000), AURORA includes detections of a large suite of nebular emission lines spanning a broad range in rest-frame wavelength. We investigate the locations of AURORA galaxies in multiple different emission-line diagrams, including traditional BPT diagrams of [O iii]λ5007/Hβ versus [N ii]λ6583/Hα, [S ii]λλ6717, 6731/Hα, and [O i]λ6300/Hα, and the ionization-metallicity diagram of [O iii]λ5007/[O ii]λ3727 (O32) versus ([O iii]λ5007+[O ii]λ3727)/Hβ (R23). We also consider a bluer rest-frame ionization-metallicity diagram introduced recently to characterize z > 10 galaxies, [Ne iii]λ3869/[O ii]λ3727 versus ([Ne iii]λ3869+[O ii]λ3727)/Hδ, as well as longer-wavelength diagnostic diagrams extending into the rest-frame near-IR: [O iii]λ5007/Hβ versus [S iii]λλ9069, 9532/[S ii]λλ6717, 6731 (S32), and He iλ1.083 μm/Paγ and [S iii]λ9532/Paγ versus [Fe ii]λ1.257μm/Paβ. With a significant boost in signal-to-noise ratio and large, representative samples of individual galaxy detections, the AURORA emission-line diagrams presented here definitively confirm a physical picture in which chemically young, α-enhanced, massive stars photoionize the interstellar medium (ISM) in distant galaxies with a harder ionizing spectrum at fixed nebular metallicity than in their z ∼ 0 counterparts. We also uncover previously unseen evolution prior to z ∼ 2 in the [O iii]λ5007/Hβ versus [N ii]λ6583/Hα diagram, which motivates deep NIRSpec observations at even higher redshift. Finally, we present the first statistical sample of rest-frame near-IR emission-line diagnostics in star-forming galaxies at high redshift. In order to truly interpret rest-frame near-IR line ratios including [Fe ii]λ1.257 μm, we must obtain better constraints on dust depletion in the high-redshift ISM.
UR - https://www.scopus.com/pages/publications/85218937394
UR - https://www.scopus.com/pages/publications/85218937394#tab=citedBy
U2 - 10.3847/1538-4357/adad68
DO - 10.3847/1538-4357/adad68
M3 - Article
AN - SCOPUS:85218937394
SN - 0004-637X
VL - 980
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 242
ER -