MOSDEF-3D

Authors

• Natalie Lam, University of California, Los AngelesFollow
• Alice E. Shapley, University of California, Los Angeles
• Ryan L. Sanders, University of KentuckyFollow
• Tuan Do, University of California, Los Angeles
• Tucker Jones, University of California Davis
• Alison Coil, University of California San Diego Health
• Mariska Kriek, Leiden Observatory Research Institute
• Bahram Mobasher, University of California Riverside
• Naveen A. Reddy, University of California Riverside
• Brian Siana, University of California Riverside
• Leonardo Clarke, University of California, Los Angeles

Abstract

We present spatially resolved rest-frame optical emission line maps of four galaxies at z ∼ 2 observed with the Keck/OH-Suppressing Infra-Red Imaging Spectrograph to study the physical conditions of the interstellar medium (ISM) at cosmic noon. Our analysis of strong emission line ratios in these galaxies reveals an offset from the local star-forming locus on the Baldwin–Phillips–Terlevich diagram but agrees with other star-forming galaxies at similar redshifts. Despite the offset toward higher [O iii] λ5008/Hβ and [N ii] λ6585/Hα, these strong line ratios remain consistent with or below the maximum starburst threshold even in the inner ∼1 kpc region of the galaxies, providing no compelling evidence for central active galactic nucleus activity. The galaxies also exhibit flat radial gas-phase metallicity gradients, consistent with previous studies of z ∼ 2 galaxies and suggesting efficient radial mixing possibly driven by strong outflows from intense star formation. Overall, our results reveal the highly star-forming nature of these galaxies, with the potential to launch outflows that flatten metallicity gradients through significant radial gas mixing. Future observations with JWST/NIRSpec are crucial to detect fainter emission lines at higher spatial resolution to further constrain the physical processes and ionization mechanisms that shape the ISM during cosmic noon.

Document Type

Article

Publication Date

5-1-2026

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 Creative Commons Attribution 4.0 licence. 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)

10.3847/1538-4357/ae5704

Archival?

Archival

Repository Citation

Lam, Natalie; Shapley, Alice E.; Sanders, Ryan L.; Do, Tuan; Jones, Tucker; Coil, Alison; Kriek, Mariska; Mobasher, Bahram; Reddy, Naveen A.; Siana, Brian; and Clarke, Leonardo, "MOSDEF-3D" (2026). Physics and Astronomy Faculty Publications. 776.
https://uknowledge.uky.edu/physastron_facpub/776