Tracing ionized gas kinematics in LBAs

The luminosities and line ratios of the narrow components are typical of giant HII regions. We interpret the broader components as ionized outflows driven by strong winds of massive stars and supernovae. In galaxies with highly complex profiles and disturbed morpholo- gies, ongoing interactions or mergers are found to contribute to the broad components.

We find outflow velocities in the range vout~200km/s to 500km/s. Simple models yield outflow mass rates of 0.20-2.72M_{sun}_/yr and mass-loading factors {eta}~0.03-0.81. We find that {eta} shows a mild increasing trend at lower stellar masses, in agreement with previous observational studies and predictions from FIRE-2 and Illustris-TNG simulations.

Compact starburst morphologies may modulate the {eta}-M* relation, showing a strong {SIGMA}_SFR_-{eta} correlation, i.e., more compact starbursts drive stronger outflows. We find a good agreement with similar findings in star-forming galaxies at high-redshift (z~2-9), including those from recent JWST observations. Our results highlight the relevance of detailed studies of the ionized gas kinematics in local UV-compact starbursts to improve our understanding of feedback processes in low-mass, rapidly star-forming galaxies