The transition of galaxy groups from an invigorating environment to a suffocating one
Abstract
At low redshift, galaxy groups are hostile environments, gradually shutting down star formation activity; but at z=1 there is evidence that groups actually induce star formation in massive galaxies. While much can be learned about this important process from wide-field, sparsely sampled redshift surveys, a complementary and necessary approach is to study a smaller, pure sample of groups in detail. Only then is it possible to robustly measure the group mass, centre and radius, and the group-to-group variations predicted by simple infall models. We propose to continue a 3 semester programme begun in 09A, to study galaxies in 16 groups at 0.8<z<1, selected from ultradeep X-ray observations. With the available data we will be able to measure the dynamical mass, stellar mass fraction, star formation rate, and the fraction of "evolved" galaxies in these systems.
- Publication:
-
NOAO Proposal
- Pub Date:
- February 2010
- Bibcode:
- 2010noao.prop..250B