Probing Star Formation Feedback at its Most Extreme
This colloquium is hosted by STScI and will be held as a fully virtual event.
3:00 PM - 4:00 PM
Feedback from massive stars and supernovae has proven to be a key ingredient in successful models of galaxy evolution. Yet much about the feedback process is still poorly understood due to a lack of direct observational constraints. To help remedy this, we have been studying a population of compact massive starburst galaxies at z~0.6 that may be similar to the progenitors of modern day massive ellipticals. HST imaging shows that the galaxies are major mergers near the point of coalescence that are undergoing a high intensity short duration circumnuclear starbursts that will form a significant fraction of their stellar mass. The galaxies host spectacular ionized and molecular gas outflows with velocities in the range of 1000 - 2500 km/s, and several show evidence that they are leaking Lyman continuum photons due near-complete gas blow-out in the star forming region. We show that the highest velocity outflows correspond to the youngest starburst ages, suggesting a scenario where progressive mass loading of the hot wind causes it to decelerate. In one object, we trace the outflow in [OII] 3727 emission and find that it extends up to 50 kpc, suggesting that these winds play a key role in transporting energy and metals into the circumgalactic medium. All together, these objects represent a unique opportunity to study the physics associated with an important evolutionary phase, and the mechanics of star formation at its most extreme.
Speaker: Christy Tremonti (University of Wisconsin-Madison)
All 2020 Fall Colloquium virtual talks are held on Wednesdays at 3:00 PM.
Please direct questions or comments to contact above. The 2020-2021 committee members are: Karoline Gilbert (STScI co-chair), Ethan Vishniac (JHU co-chair), Graeme Addison (JHU), Martha Boyer (STScI), Joshua Peek (STScI), Kevin Schlaufman (JHU), and Raymond Simons (STScI).