A 100 kpc Galactic Wind Feeding the Circumgalactic Medium
Alison Coil
UC San Diego
The origin of the metal-enriched and massive circumgalactic medium (CGM) remains
elusive. Theory points to expulsion from galaxies through outflowing winds as a dominant
mechanism, but no directly-imaged winds reach far into the physical scale of the CGM.
Using KCWI on Keck, we have discovered an enormous (100 kpc x 80 kpc) ionized gas
outflow directly connecting the galactic wind from a massive, compact starburst galaxy
at z~0.5 to its surrounding CGM. This wind is depositing metal-enriched gas to over 20
times the stellar radius of the galaxy through an hourglass-shaped nebula; the outflow
is the largest galactic wind ever observed. Multiple gas phases (ionized, neutral, and
molecular) are observed extending to 20 kpc moving at extremely high speeds up to ~1500
km/s. This outflow may be feeding the CGM both by depositing gas directly and by
entraining and cooling hot halo gas. I will further discuss the galaxy sample that this
wind was discovered within and on-going work to characterize the properties of both the
host galaxies and their outflows.
Date: | Jeudi, 17 février 2022 |
Time: | 11:30 |
Where: | Université de Montréal |
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