2024ApJ...974...22Z

The Large Magellanic Cloud (LMC) is home to many H II regions, which may lead to significant outflows. We examine the LMC's multiphase gas (T∼10^4–5 K) in H I, S II, Si IV, and C IV using 110 stellar sight lines from the Hubble Space Telescope's Ultraviolet Legacy Library of Young Stars as Essential Standards program. We develop a continuum fitting algorithm based on the concept of Gaussian process regression and identify reliable LMC interstellar absorption over v_helio = 175-375 km s^–1. Our analyses show disk-wide ionized outflows in Si IV and C IV across the LMC with bulk velocities of ∣v_out, bulk_∣ ∼ 20-60 km s^–1, which indicates that most of the outflowing mass is gravitationally bound. The outflows' column densities correlate with the LMC's star formation rate surface densities (Σ_SFR), and the outflows with higher Σ_SFR tend to be more ionized. Considering outflows from both sides of the LMC as traced by C IV, we conservatively estimate a total outflow rate of ${\dot{M}}_{\mathrm{out}}\gtrsim 0.03\,{M}_{\odot }{\mathrm{yr}}^{-1}$ and a mass-loading factor of η ≳ 0.15. We compare the LMC's outflows with those detected in starburst galaxies and simulation predictions, and find a universal scaling relation of $| {v}_{\mathrm{out},\ \mathrm{bulk}}| \propto {{\rm{\Sigma }}}_{\mathrm{SFR}}^{0.23}$ over a wide range of star-forming conditions (Σ_SFR ∼ 10^–4.5-10²M_⊙ _yr^–1 kpc^–2). Lastly, we find that the outflows are corotating with the LMC's young stellar disk and the velocity field does not seem to be significantly impacted by external forces; we thus speculate on the existence of a bow shock leading the LMC, which may have shielded the outflows from ram pressure as the LMC orbits the Milky Way.