Galaxy Clusters and the Butcher-Oemler Effect:
Emily Cross and Kristine Salters
Galaxy Transformation by Environment
Environment &Population
“Like cities, each cluster has unique characteristics and population demographics: Coma, Virgo, and the Local Group are as different from each other as Toronto, Bangkok, and Rio de Janeiro”
(S&T: January 1988, page 16).
The Butcher-Oemler Effect
Galaxy cluster with high redshift have a higher blue star forming spiral population
Low redshift, low blue spiral population
Red shift 101
The
BOEffect
Galaxy Evolution
RED SHIFT
The evolutionary Sequence
Infalling spiral galaxy
Galaxy cluster
Clusters disrupting Star Formation
Merging Starburst Ram pressure stripping Tidal disruption
SF completely exhausted
The youths
But what about the awkward teen phase of galaxy evolution?
We had never seen the phase between the young blue spirals and the old red ellipticals until November
of 2008
Photo
The evolving properties of galaxies in clusters offer a unique opportunity to connect evolution on scales ranging from individual galaxies to overall cosmic evolution