BEGIN:VCALENDAR
VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:0
UID:UW-Physics-Event-2792
DTSTART:20120927T203000Z
DTEND:20120927T220000Z
DTSTAMP:20260420T021531Z
LAST-MODIFIED:20120912T145356Z
LOCATION:4421 Sterling Hall
SUMMARY:Early Star Forming Galaxies and the Reionization of the Univer
 se\, Astronomy Colloquium\, Dan Stark\, University of Arizona
DESCRIPTION:The events of the first billion years of cosmic history ar
 e one of the final frontiers  in the quest to trace the history of the
  Universe from its origins to the present day.  Exploration of this un
 charted era is driven by the desire to locate and understand the natur
 e of the first stars and galaxies and to characterize their contributi
 on to the reionization of hydrogen.  With the installation of the Wide
  Field Camera 3 (WFC3) onboard the Hubble Space Telescope\, the cosmic
  frontier has been pushed back to just 500 Myr after the Big Bang\, de
 livering the first census of star formation activity in the reionizati
 on era.  Deep spectroscopy of these early systems is now providing ins
 ight into the properties of primitive galaxies while simultaneously co
 nstraining the progress of reionization.   I will summarize the result
 s from these studies\, providing tentative evidence that reionization 
 comes to an end between z~7 and z~6\, while revealing some tension in 
 the ability of star-forming galaxies to achieve reionization by z=6.  
 Finally I will discuss how spectroscopic studies of low mass gravitati
 onally- lensed galaxies at moderate and high redshift are improving ou
 r understanding of the formation of early galactic systems\, hinting a
 t an increased transmission  of ionizing radiation into the intergalac
 tic medium and a harder ionizing spectrum.
URL:https://www.physics.wisc.edu/events/?id=2792
END:VEVENT
END:VCALENDAR