BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//ZContent.net//ZapCalLib 1.0//EN
CALSCALE:GREGORIAN
METHOD:PUBLISH
BEGIN:VEVENT
DTSTART;TZID=Atlantic/Canary:20170518T103000
DTEND;TZID=Atlantic/Canary:20170518T113000
UID:iactalks-1028
X-WR-CALNAME: IAC Talks: Open Astronomy Seminars
X-ORIGINAL-URL: /iactalks/Talks/view/1028
CREATED:2017-05-18T10:30:00+01:00
X-WR-CALDESC: IAC Talks upcomming talks
SUMMARY:The Ubiquity of Coeval Starbursts in Massive Galaxy Cluster Progeni
 tors
DESCRIPTION:The Ubiquity of Coeval Starbursts in Massive Galaxy Cluster Pro
 genitors\nProf. Caitlin Casey\n\nThe Universe’s largest galaxy clust
 ers likely built the majority of their massive >10^11 M⊙ galaxies in 
 simultaneous, short-lived bursts of activity well before virialization. Th
 e most challenging observational hurdle in identifying such pre-virialized
  “protoclusters” is their very large volumes, ~10^4 comoving M
 pc^3 at z > 2, subtending areas ~half a degree on the sky. Thus the con
 trast afforded by an overabundance of very rare galaxies in comparison to 
 the background can more easily distinguish overdense structures from the s
 urrounding, normal density field. There are now five well-known 2 < z &
 lt; 3 proto-clusters from the literature which are found to contain up to 
 12 dusty starbursts or luminous AGN galaxies each, a phenomenon that is un
 likely to occur by chance even in overdense environments. I will discuss t
 hese in addition to some higher-redshift (4 < z < 5.5) groups, whose
  evolutionary fate is less clear. Measurements of DSFGs’ gas depleti
 on times suggest that they are indeed short-lived on ~100 Myr timescales, 
 and accordingly the probability of finding a structure containing more tha
 n 8 such systems is 0.2%, unless their ‘triggering’ is correla
 ted on very large spatial scales, ~10 Mpc across. The volume density of DS
 FG-rich protoclusters is found to be comparable to all >10^15 M⊙ gala
 xy clusters in the nearby Universe, a factor of five larger than expected 
 in some simulations. Some tension yet exists between measurements and simu
 lations. However, improved observations of protoclusters over large region
 s of sky will certainly shed more light on the assembly of galaxy clusters
 , thus fundamental parameters governing cosmology, and also the role of en
 vironment in shaping the formation and evolution of galaxies.
END:VEVENT
END:VCALENDAR