Abstract
Abstract
We present the first spectroscopically resolved Hα emission map of the Large Magellanic Cloud’s (LMC) galactic wind. By combining new Wisconsin H-alpha Mapper observations (I
Hα
≳ 10 mR) with existing H i 21 cm emission observations, we (1) mapped the LMC’s nearside galactic wind over a local standard of rest (LSR) velocity range of +50 ≤ v
LSR ≤ +250 km s−1, (2) determined its morphology and extent, and (3) estimated its mass, outflow rate, and mass-loading factor. We observe Hα emission from this wind to typically 1° off the LMC’s H i disk. Kinematically, we find that the diffuse gas in the warm-ionized phase of this wind persists at both low (≲100 km s−1) and high (≳100 km s−1) velocities, relative to the LMC’s H i disk. Furthermore, we find that the high-velocity component spatially aligns with the most intense star-forming region, 30 Doradus. We, therefore, conclude that this high-velocity material traces an active outflow. We estimate the mass of the warm (T
e
≈ 104 K) ionized phase of the nearside LMC outflow to be
for the combined low and high-velocity components. Assuming an ionization fraction of 75% and that the wind is symmetrical about the LMC disk, we estimate that its total (neutral and ionized) mass is
, its mass-flow rate is
, and its mass-loading factor is η ≈ 4.54. Our average mass-loading factor results are roughly a factor of 2.5 larger than previous Hα imaging and UV absorption line studies, suggesting that those studies are missing nearly half the gas in the outflows.
Publisher
American Astronomical Society
Subject
Space and Planetary Science,Astronomy and Astrophysics
Cited by
5 articles.
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