Characterization of Two Cool Galaxy Outflow Candidates Using Mid-Infrared Emission from Polycyclic Aromatic Hydrocarbons
Abstract
We characterize two candidate cool galactic outflows in two relatively low mass, highly inclined Virgo cluster galaxies: NGC4424 and NGC4694. Previous analyses of observations using the Atacama Large Millimeter Array (ALMA) carbon monoxide (CO) line emission maps did not classify these sources as cool outflow hosts. Using new high sensitivity, high spatial resolution, JWST mid-infrared photometry in the polycyclic aromatic hydrocarbon (PAH)-tracing F770W band, we identify extended structures present off of the stellar disk. The identified structures are bright in the MIRI F770W and F2100W bands, suggesting they include PAHs as well as other dust grains. As PAHs have been shown to be destroyed in hot, ionized gas, these structures are likely to be outflows of cool (TK) gas. This work represents an exciting possibility for using mid infrared observations to identify and measure outflows in lower mass, lower star formation galaxies.
Cite
@article{arxiv.2509.12058,
title = {Characterization of Two Cool Galaxy Outflow Candidates Using Mid-Infrared Emission from Polycyclic Aromatic Hydrocarbons},
author = {Jessica Sutter and Karin Sandstrom and Ryan Chown and Oleg Egorov and Adam K. Leroy and Jérémy Chastenet and Alberto Bolatto and Thomas G. Williams and Daniel A. Dale and Amirnezam Amiri and Médéric Boquein and Yixian Cao and Simthembile Dlamini and Éric Emsellem and Hsi-An Pan and Debosmita Pathak and Hwihyun Kim and Ralf S. Klessen and Hannah Koziol and Erik Rosolowsky and Sumit K. Sarbadhicary and Eva Schinnerer and David A. Thilker and Leonardo Úbeda and Tony Weinbeck},
journal= {arXiv preprint arXiv:2509.12058},
year = {2025}
}
Comments
Accepted for publication in The Astrophysical Journal Letters, 12 pages, 4 figures and 1 table