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VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:0
UID:UW-Physics-Event-4956
DTSTART:20181115T213000Z
DTEND:20181115T230000Z
DTSTAMP:20260419T075955Z
LAST-MODIFIED:20181112T135700Z
LOCATION:4421 Sterling Hall\, Coffee and Cookies 3:30 PM\, Talk begins
  at 3:45 PM
SUMMARY:The Journey or the Destination: Isolating the Origin of the Ph
 ysics Driving Gas Conditions in Galaxy Nuclei\, Astronomy Colloquium\,
  Elisabeth Mills\, Brandeis University
DESCRIPTION:Centers of galaxies are some of the most extreme objects i
 n our universe: hosting starbursts and active supermassive black holes
  that can launch jets and winds far outside the compact galaxy nucleus
 . While there are relics of an active past in the center of our own Mi
 lky Way\, at present it does not exhibit any of this activity. However
 \, the central 300 parsecs of our Galaxy does contain a sizable reserv
 oir of molecular gas that is the fuel for future star formation and bl
 ack hole accretion. Constraining the physical conditions of this gas i
 s critical for understanding how this reservoir will evolve to influen
 ce future activity in the Milky Way’s nucleus. Determining the origi
 n of these conditions is also key to determining whether the same phys
 ics that govern gas conditions in this region can help us interpret mo
 re distant and active galaxy nuclei. I will present the results of my 
 recent work following the changes in physical properties of this gas a
 s it approaches the black hole\; increasing in temperature\, density\,
  and turbulence\, while largely resisting the onset of star formation.
  This work provides evidence that the extreme gas conditions in this r
 egion are driven largely by infall processes: the journey it takes to 
 reach the central parsecs\, rather than the energetic phenomena (super
 novae\, cosmic rays\, massive star winds\, UV radiation\, and occasion
 al X-ray flaring) encountered at its destination. However\, as our Gal
 actic center is relatively inactive\, the next challenge is determinin
 g the extent to which the understanding gained from a detailed study o
 f this region can be applied to more active systems. I will discuss ea
 rly results from my ALMA program to make parsec-scale observations of 
 the ionized and molecular gas in the center of NGC 253\, a nearby gala
 xy with an order of magnitude more star formation and molecular gas th
 at hosts a massive molecular outflow. Comparison of these two galaxy c
 enters will isolate the gas conditions that both govern and are influe
 nced by a nuclear starburst\, and allow the definition of local templa
 tes for understanding the physics of this feedback process.  <br>
\n 
URL:https://www.physics.wisc.edu/events/?id=4956
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