Three papers I see cited frequently in the context of supporting the view that galaxies are "transformed" from star-forming late types into dead early types as they fall into rich clusters are
Poggianti et al (1999),
Balogh et al (2000), and
Kodama & Bower (2001). The odd thing is that all three of these papers actually conclude that any transformation that occurs must be occuring on very long timescales (longer than 1 Gyr), because they in fact find
no direct evidence of the infall at all! The
only evidence that there is transformation with infall is that the galaxies inside the clusters look different from those outside.
It may sound crazy, but the data are consistent with a picture in which the morphological and star-formation properties of galaxies are in fact set at a relatively early time, before infall, and the relationship with environment comes from the fact that the galaxies that find themselves inside clusters come from a special (ie, not representative) set of environments and initial conditions.
Today I worked on the problem of putting this argument, or a softened version of it, into the post-starburst environments paper.
What's really crazy is that while you people are engaged in your theoretical posturing, a giant comet is coming to crush us all! NASA tried to stop it with their comet buster, but it looks like we're all going to die! The few who manage to survive will be fighting over cans of beans, not discussing infall regions. Wake up!
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