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PRODID:UW-Madison-Physics-Events
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UID:UW-Physics-Event-1671
DTSTART:20091103T214500Z
DTEND:20091103T230000Z
DTSTAMP:20260416T185928Z
LAST-MODIFIED:20091026T122135Z
LOCATION:3425 Sterling Hall
SUMMARY:Can Quasars Quench Star Formation?\, Astronomy Colloquium\, Ch
 risty Tremonti\, UW Astronomy Dept
DESCRIPTION:Since quasars were first recognized as cosmological source
 s their relation to galaxies has been a puzzle.  We now know that quas
 ars are powered by accretion of gas onto supermassive black holes at t
 he centers of massive galaxies.  What continues to elude our understan
 ding is the impact that quasars have on their host galaxies.  Recent n
 umerical simulations suggest that quasars can drive powerful gas outfl
 ows that ultimately bring about an end to star formation and black hol
 e activity.  I will discuss observations designed to directly test thi
 s hypothesis.  Because gas outflows are challenging to observe in the 
 presence of a bright quasar\, our study focuses on a sample of  galaxi
 es that are a few 100 million years past the peak of their star format
 ion and black hole activity.  In these 'post-starburst' galaxies we fi
 nd evidence for outflowing cool gas with velocities upwards of 1000 km
 /s.  We consider the energetics of the gas and argue that quasars play
  a significant role in removing gas from galaxies and quenching star f
 ormation. 
URL:https://www.physics.wisc.edu/events/?id=1671
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