SQuIGGL⃗E: Ubiquitous Cool Gas Outflows with Large Mass-Loading Factors in z∼0.7 Post-starburst Galaxies
Abstract
While recent James Webb Space Telescope studies have highlighted cool gas outflows as an important mechanism for rapid quenching at z≳2, such space-based spectroscopic samples remain limited in size. In this work, we search for and characterize cool gas outflows traced by Fe II λλ2586,2600 and Mg II λλ2796,2803 absorption in post-starburst galaxies (PSBs) at 0.5<z<0.9, which are accessible to ground-based spectroscopy. Utilizing the SQuIGGL⃗E survey containing over 1300 PSBs, we stack spectra in bins of stellar mass, (specific) star formation rate, burst mass, burst mass fraction, and time since quenching. We observe blueshifted line centroids indicative of outflows in all stacks except the one containing galaxies that quenched more than 260 Myr ago. Outflow velocities decline with increasing time since quenching, while showing little correlation with other galaxy properties. The inferred outflows have large mass loading factors of 1 -- 120, maximum velocities above the interstellar medium escape velocities of their host galaxies, and energy and momentum fluxes exceeding those expected from the current star formation. Our results suggest that cool gas outflows are ubiquitous in intermediate-redshift PSBs and are likely relic outflows launched by previous starburst or AGN activity. These outflows have the potential to quench star formation by transporting gas into the galactic halos, consistent with outflows playing an important role in rapid quenching from intermediate to high redshift.
Related
- Ubiquitous nuclear disks and bars embedded in massive galaxies in the cosmic morning
- Tracing gas outflows in molecular gas-rich galaxies with the SKA
- Link between the properties of circumgalactic outflows and the recent star formation history of their host galaxies
- The Pandora project. II: how non-thermal physics drives bursty star formation and temperate mass-loaded outflows in dwarf galaxies
- The Evolution of the Circumgalactic Medium after a starburst in DESI Post-Starburst Galaxies
BibTeX
@misc{luo2026squiggle,
title = {{SQuIGG$\vecL$E: Ubiquitous Cool Gas Outflows with Large Mass-Loading Factors in $z\sim0.7$ Post-starburst Galaxies}},
author = {Yuanze Luo and Justin S. Spilker and David J. Setton and Timothy Heckman and Rachel Bezanson and Vincenzo R. D'Onofrio and Alex Geiger and Andy D. Goulding and Jenny E. Greene and Kate Rowlands and Katherine A. Suess and Elizabeth Taylor and Margaret E. Verrico and Andrew Weldon and Vivienne Wild and Pengpei Zhu},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.31308},
eprint = {2609.31308},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.31308},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - SQuIGGL⃗E: Ubiquitous Cool Gas Outflows with Large Mass-Loading Factors in z∼0.7 Post-starburst Galaxies
AU - Yuanze Luo
AU - Justin S. Spilker
AU - David J. Setton
AU - Timothy Heckman
AU - Rachel Bezanson
AU - Vincenzo R. D'Onofrio
AU - Alex Geiger
AU - Andy D. Goulding
AU - Jenny E. Greene
AU - Kate Rowlands
AU - Katherine A. Suess
AU - Elizabeth Taylor
AU - Margaret E. Verrico
AU - Andrew Weldon
AU - Vivienne Wild
AU - Pengpei Zhu
PY - 2026
DA - 2026/09/25
PB - arXiv
DO - 10.48550/arxiv.2609.31308
UR - https://arxiv.org/abs/2609.31308
AB - While recent James Webb Space Telescope studies have highlighted cool gas outflows as an important mechanism for rapid quenching at z≳2, such space-based spectroscopic samples remain limited in size. In this work, we search for and characterize cool gas outflows traced by Fe II λλ2586,2600 and Mg II λλ2796,2803 absorption in post-starburst galaxies (PSBs) at 0.5<z<0.9, which are accessible to ground-based spectroscopy. Utilizing the SQuIGGL⃗E survey containing over 1300 PSBs, we stack spectra in bins of stellar mass, (specific) star formation rate, burst mass, burst mass fraction, and time since quenching. We observe blueshifted line centroids indicative of outflows in all stacks except the one containing galaxies that quenched more than 260 Myr ago. Outflow velocities decline with increasing time since quenching, while showing little correlation with other galaxy properties. The inferred outflows have large mass loading factors of 1 -- 120, maximum velocities above the interstellar medium escape velocities of their host galaxies, and energy and momentum fluxes exceeding those expected from the current star formation. Our results suggest that cool gas outflows are ubiquitous in intermediate-redshift PSBs and are likely relic outflows launched by previous starburst or AGN activity. These outflows have the potential to quench star formation by transporting gas into the galactic halos, consistent with outflows playing an important role in rapid quenching from intermediate to high redshift.
ER -