Speaker
Arjan Bik
(Stockholm University)
Description
The feedback of massive stars and star clusters has a dramatic effect on the
surrounding interstellar matter (ISM), affecting the shape and fate of galaxies as a
whole. The molecular ISM in which the stars are formed is transformed to a warm
ionized medium by means of the Lyman continuum output as well as the stellar wind
and supernovae of the massive stars in the galaxy. The large amounts of energy put in
by the massive stars can lead to galactic scale outflows and to changes in the
star-formation activity of galaxies.
We present high quality VLT/MUSE observations of ESO 338-IG04. The super star
clusters in this Blue Compact Galaxy have strongly altered the state of the ISM.
Analysis of the optical emission lines reveals the physical conditions of the ionized
gas in the large halo surrounding this galaxy. Several large scale outflows are
identified. This is compared to the properties of the star clusters as derived from
SED fitting. We find that the youngest and most massive clusters are responsible for
the highest ionization gas. Typically, the youngest clusters are surrounded by higher
density (and pressure) gas, suggesting they are still partly embedded in their natal
HII region. Our analysis suggests that the central starburst in ESO 338 highly
ionized the entire central part of the galaxy and which is expanding into the
lower-ionization outskirts of the galaxy giving rise to shocked gas.
Primary author
Arjan Bik
(Stockholm University)
