BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Processing of ices in protoplanetary disks: why chemistry matters 
 when making planets - Catherine Walsh (Leeds)
DTSTART:20170510T150000Z
DTEND:20170510T160000Z
UID:TALK72240@talks.cam.ac.uk
CONTACT:Ed Gillen
DESCRIPTION:Planets are built from material - dust\, gas\, and ice - in th
 e dense\, dark\, and relatively cool midplanes of protoplanetary disks.  T
 here currently exist two schools of thought on the composition of disk mid
 planes and thus planet-building material.  The first\, and perhaps most in
 tuitive\, is that the midplane has a fixed composition that varies only ac
 ross snow (or ice) lines that mark the boundary beyond which a particular 
 volatile exists solely in the ice phase.  This assumption is widely invoke
 d in the exoplanet community to relate observed atmospheric abundances to 
 a formation location and also by the planet population synthesis community
  to set the initial composition of planetesimal 'seeds'. The second consid
 ers alteration of the composition of planet-building material via chemical
  reactions in the gas and on the surfaces of small dust grains (<~ 1 mm). 
  This can occur during the disk formation stage (from cloud to disk)\, and
  during protoplanetary disk evolution and dispersal (from disk to planet).
   Hence\, to what extent chemistry affects the composition of planet-build
 ing material depends upon the timescale of planetesimal growth relative to
  the timescale of disk formation and dispersal.  In this talk\, I will sho
 w results from chemical kinetics calculations of protoplanetary disks to i
 llustrate the effects of chemistry on the composition of planet-building m
 aterial during disk formation and evolution.
LOCATION:Martin Ryle Seminar Room\, Kavli Institute
END:VEVENT
END:VCALENDAR