Observed Timescales of Stellar Feedback in Star-forming, Low-mass Galaxies
June 2026 • 2026AJ....171..358H
Abstract • Understanding the timescales of atomic gas turbulence is crucial to understanding the interplay between star formation and the interstellar medium (ISM). To investigate the timescales of turbulence low-mass galaxies (106.8 < M⊙ < 109), this study combines (i) temporally resolved star formation histories (SFHs) derived from color─magnitude diagrams with (ii) kinematic data of the atomic and ionized hydrogen in a large sample of nearby, star-forming, low-mass galaxies. To best understand the timescales involved, SFHs and gas kinematics were analyzed in 400 × 400 pc regions to capture the local impacts of star formation. No strong correlation was found between the ionized gas velocity dispersion and the star formation activity over the past 5─500 Myr. In contrast, a consistent and significant correlation between the atomic hydrogen turbulence measures and the star formation activity t ≥ 100 Myr ago was identified. This correlation suggests the star formation activity and atomic gas are coupled on this timescale. This connection between star formation activity >100 Myr ago, and the H I turbulence properties, may be related to the timescales over which turbulence decays in the ISM. Additionally, the results demonstrate a possible difference in the global and local turbulence properties of low-mass galaxies.
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