The JWST EXCELS survey

Authors

• Elizabeth Taylor, University of EdinburghFollow
• Adam C. Carnall, University of Edinburgh
• David Maltby, University of Nottingham
• Omar Almaini, University of Nottingham
• Ho Hin Leung, University of Edinburgh
• Struan D. Stevenson, University of Edinburgh
• Andrea Negri, University of Seville
• Fergus Cullen, University of Edinburgh
• Vivienne Wild, University of St Andrews
• Ross J. McLure, University of Edinburgh
• Alice E. Shapley, University of California, Los Angeles
• Karla Z. Arellano-Córdova, University of Edinburgh
• Ryan Begley, Armagh Observatory
• Cecilia Bondestam, University of Edinburgh
• Thomas de Lisle, University of Nottingham
• Callum T. Donnan, NSF's National Optical-Infrared Astronomy Research Laboratory
• James S. Dunlop, University of Edinburgh
• Richard Ellis, University College London
• Guillaume Hewitt, University of Nottingham
• Anton M. Koekemoer, Space Telescope Science Institute
• Feng Yuan Frey Liu, University of Edinburgh
• Derek J. McLeod, University of Edinburgh
• Kate Rowlands, Space Telescope Science Institute
• Ryan L. Sanders, University of KentuckyFollow
• Dirk Scholte, University of Edinburgh
• Maya Skarbinski, Johns Hopkins University
• Thomas M. Stanton, University of Edinburgh

Abstract

We investigate the presence and origin of neutral gas outflows and inflows in 13 post-starburst and quiescent galaxies at redshifts (Formula presented), using James Webb Space Telescope NIRSpec spectroscopy from the EXCELS survey. Na d absorption profiles reveal that 3 out of 13 exhibit blueshifted absorption indicative of outflows, and a further 2 objects show signs of inflowing gas. Outflow velocities range from (Formula presented) 300 to 1200 km s(Formula presented), and we find gas flows are detected exclusively in objects that quenched (Formula presented)  Myr ago. We derive mass outflow rates over two orders of magnitude higher than current levels of star formation in our sample, indicating that the winds are unlikely to be driven by supernovae. The majority of the outflow sample have anomalously high energy and momentum outflow rates compared to those predicted for current levels of star formation or active galactic nucleus (AGN) activity. We conclude that we are likely observing fossil outflows driven by previous, more luminous AGN activity which has since faded. We then compare with the eagle simulation to explore a potential ‘outflow cycle’, finding that our observations are consistent with a model in which (Formula presented) quiescent galaxies undergo short (Formula presented)  Myr periods of AGN activity strong enough to drive outflows, which occur every (Formula presented) 40 Myr on average. This AGN activity drives observable outflows that persist for up to (Formula presented)  Myr after the AGN fades, followed by a (Formula presented)  Myr lull, and a subsequent short inflow, which eventually re-ignites AGN activity, and the cycle repeats.

Document Type

Article

Publication Date

7-1-2026

Notes/Citation Information

Publisher Copyright: © The Author(s) 2026. Published by Oxford University Press on behalf of Royal Astronomical Society. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.

Digital Object Identifier (DOI)

10.1093/mnras/stag918

Archival?

Archival

Repository Citation

Taylor, Elizabeth; Carnall, Adam C.; Maltby, David; Almaini, Omar; Leung, Ho Hin; Stevenson, Struan D.; Negri, Andrea; Cullen, Fergus; Wild, Vivienne; McLure, Ross J.; Shapley, Alice E.; Arellano-Córdova, Karla Z.; Begley, Ryan; Bondestam, Cecilia; de Lisle, Thomas; Donnan, Callum T.; Dunlop, James S.; Ellis, Richard; Hewitt, Guillaume; Koekemoer, Anton M.; Liu, Feng Yuan Frey; McLeod, Derek J.; Rowlands, Kate; Sanders, Ryan L.; Scholte, Dirk; Skarbinski, Maya; and Stanton, Thomas M., "The JWST EXCELS survey" (2026). Physics and Astronomy Faculty Publications. 767.
https://uknowledge.uky.edu/physastron_facpub/767