A Census of Na D–Traced Neutral Interstellar Medium and Outflows at 0.6 < z < 4
9 affiliations
- 1University of Arizona
- 2University of Cambridge
- 3University of Copenhagen
- 4University of Oxford
- 5Scuola Normale Superiore
- 6The Pennsylvania State University
- 7Centro de Astrobiología (CAB)
- 8Space Telescope Science Institute
- 9Max-Planck-Institut für extraterrestrische Physik (MPE)
Abstract
We present a statistical census of the Na D–traced neutral interstellar medium (ISM) and outflows in 309 galaxies at 0.6 < z < 4 using JWST/NIRSpec medium-resolution spectroscopy from the SMILES, JADES, Blue Jay, and Aurora surveys. After subtracting the stellar continuum, we model Na D λλ 5890, 5896 and identify 73 Na D ISM absorptions, including 63 robust (4 in broad-line active galactic nuclei, AGN) and 10 tentative detections. Of the robust detections, 88% are found in massive galaxies ( log ( M * / M ⊙ ) > 10 ), and 12% are in lower-mass systems. At high mass, ISM absorption is seen in both star-forming and quiescent galaxies, whereas in lower-mass systems, it is observed only in star-forming galaxies. In massive quiescent galaxies, Na D detectability appears linked to star formation history: it is preferentially detected in older systems with larger 4000 Å breaks and younger, rapidly quenching galaxies with strong Balmer absorption H δ A . We identify Na D outflows in 25 galaxies, revealing a possible dichotomy in driving mechanisms between star-forming and quiescent galaxies. In star-forming galaxies, outflow properties correlate with star formation properties, consistent with a star-formation-driven origin. In quiescent galaxies, however, outflows are not associated with residual star formation and often require more energy than such star formation can provide. Together with the high AGN fraction among outflow-detected quiescent galaxies, this suggests that AGN dominate Na D–traced neutral outflows in cosmic noon quiescent systems. We further identify four quiescent galaxies with possible AGN fossil outflows, suggesting that AGN-driven outflows can persist beyond the active accretion phase and may help maintain quiescence.
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BibTeX
@article{sun2026census,
title = {{A Census of Na D–Traced Neutral Interstellar Medium and Outflows at 0.6 < z < 4}},
author = {Yang Sun and Zhiyuan Ji and Francesco D’Eugenio and Yongda Zhu and George H. Rieke and William M. Baker and Andrew J. Bunker and Stefano Carniani and Jakob M. Helton and Michele Perna and Pablo G. Pérez-González and Pierluigi Rinaldi and Hannah Übler and Christopher N. A. Willmer},
journal = {The Astrophysical Journal},
year = {2026},
month = nov,
doi = {10.3847/1538-4357/aeaccf},
url = {https://iopscience.iop.org/article/10.3847/1538-4357/aeaccf},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - A Census of Na D–Traced Neutral Interstellar Medium and Outflows at 0.6 < z < 4
AU - Yang Sun
AU - Zhiyuan Ji
AU - Francesco D’Eugenio
AU - Yongda Zhu
AU - George H. Rieke
AU - William M. Baker
AU - Andrew J. Bunker
AU - Stefano Carniani
AU - Jakob M. Helton
AU - Michele Perna
AU - Pablo G. Pérez-González
AU - Pierluigi Rinaldi
AU - Hannah Übler
AU - Christopher N. A. Willmer
PY - 2026
DA - 2026/11/04
JO - The Astrophysical Journal
DO - 10.3847/1538-4357/aeaccf
UR - https://iopscience.iop.org/article/10.3847/1538-4357/aeaccf
AB - We present a statistical census of the Na D–traced neutral interstellar medium (ISM) and outflows in 309 galaxies at 0.6 < z < 4 using JWST/NIRSpec medium-resolution spectroscopy from the SMILES, JADES, Blue Jay, and Aurora surveys. After subtracting the stellar continuum, we model Na D λλ 5890, 5896 and identify 73 Na D ISM absorptions, including 63 robust (4 in broad-line active galactic nuclei, AGN) and 10 tentative detections. Of the robust detections, 88% are found in massive galaxies ( log ( M * / M ⊙ ) > 10 ), and 12% are in lower-mass systems. At high mass, ISM absorption is seen in both star-forming and quiescent galaxies, whereas in lower-mass systems, it is observed only in star-forming galaxies. In massive quiescent galaxies, Na D detectability appears linked to star formation history: it is preferentially detected in older systems with larger 4000 Å breaks and younger, rapidly quenching galaxies with strong Balmer absorption H δ A . We identify Na D outflows in 25 galaxies, revealing a possible dichotomy in driving mechanisms between star-forming and quiescent galaxies. In star-forming galaxies, outflow properties correlate with star formation properties, consistent with a star-formation-driven origin. In quiescent galaxies, however, outflows are not associated with residual star formation and often require more energy than such star formation can provide. Together with the high AGN fraction among outflow-detected quiescent galaxies, this suggests that AGN dominate Na D–traced neutral outflows in cosmic noon quiescent systems. We further identify four quiescent galaxies with possible AGN fossil outflows, suggesting that AGN-driven outflows can persist beyond the active accretion phase and may help maintain quiescence.
SN - 1538-4357
SN - 0004-637X
ER -