SQuIGGLE: Radio AGN Found Predominantly in Young, Gas-rich Post-starburst Galaxies at z ~ 0.7

@misc{donofrio2026squiggle,
  title = {{SQuIGGLE: Radio AGN Found Predominantly in Young, Gas-rich Post-starburst Galaxies at z ~ 0.7}},
  author = {Vincenzo R. D'Onofrio and Justin S. Spilker and Krista L. Smith and Rachel Bezanson and Robert Feldmann and Alex J. Geiger and Andy D. Goulding and Jenny E. Greene and Mariska Kriek and Anika Kumar and Yuanze Luo and Desika Narayanan and David J. Setton and Katherine A. Suess and Margaret E. Verrico and Pengpei Zhu},
  howpublished = {arXiv},
  year = {2026},
  month = oct,
  doi = {10.48550/arxiv.2610.19146},
  eprint = {2610.19146},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2610.19146},
}

TY  - UNPB
TI  - SQuIGGLE: Radio AGN Found Predominantly in Young, Gas-rich Post-starburst Galaxies at z ~ 0.7
AU  - Vincenzo R. D'Onofrio
AU  - Justin S. Spilker
AU  - Krista L. Smith
AU  - Rachel Bezanson
AU  - Robert Feldmann
AU  - Alex J. Geiger
AU  - Andy D. Goulding
AU  - Jenny E. Greene
AU  - Mariska Kriek
AU  - Anika Kumar
AU  - Yuanze Luo
AU  - Desika Narayanan
AU  - David J. Setton
AU  - Katherine A. Suess
AU  - Margaret E. Verrico
AU  - Pengpei Zhu
PY  - 2026
DA  - 2026/10/13
PB  - arXiv
DO  - 10.48550/arxiv.2610.19146
UR  - https://arxiv.org/abs/2610.19146
AB  - The processes that rapidly quench massive galaxies and maintain their quiescence remain poorly understood. Substantial molecular gas reservoirs can survive this shutdown in post-starburst galaxies, raising the question of what prevents the remaining gas from efficiently forming stars. We present deep, subarcsecond VLA 6 GHz observations of 52 massive SQuIGGLE post-starburst galaxies at z∼0.7 to test the prevalence and mechanical impact of radio activity during the gas-rich post-burst phase. We detect 6 GHz continuum emission in 18/52 galaxies (≈35\%), spanning log(L_1.4 GHz/W Hz^−1)≃23.0--$25.0$ and generally exceeding the contributions expected from ongoing star formation and the fading starburst, favoring an AGN origin. Ancillary data at other wavelengths provide little evidence for a population of luminous, radiatively efficient AGN, suggesting that these sources are instead dominated by comparatively weak, mechanically powered radio AGN. Radio activity is strongly concentrated within the first ∼200 Myr post-burst and is predominantly associated with galaxies retaining substantial gas reservoirs. Above a common radio luminosity threshold, the radio detection fraction is enhanced by a factor of ≈2.5 relative to the radio AGN candidate fraction in mass- and redshift-matched quiescent LEGA-C galaxies, primarily due to lower power sources. For efficient jet--ISM coupling, the inferred mechanical power could supply the approximate energy required to unbind the molecular gas on timescales comparable to its observed decline. Together, these results identify a population of radiatively inefficient AGN hosted predominantly by young, gas-rich post-starburst galaxies at z∼0.7 and suggest that they may have a role in maintaining inefficient star formation.
ER  -