NOAO > Observing Info > Approved Programs > 2011A-0127
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NOAO > Observing Info > Approved Programs > 2011A-0127 |
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PI: Michael Balogh, University of Waterloo, mbalogh@uwaterloo.ca
Address: Department of Physics and Astronomy, Astronomy Group, Waterloo, Ontario, N2L 3G1, Canada
CoI: Sean McGee, University of Durham
CoI: Laura Parker, McMaster University
CoI: Richard Bower, University of Durham
CoI: John Mulchaey, Carnegie Institution of Washington (Carnegie Obs.)
CoI: Alexis Finoguenov, MPE, Garching
CoI: Dave Wilman, MPE, Garching
CoI: Jennifer Connelly, MPE, Garching
Title: The transition of galaxy groups from an invigorating environment to a suffocating one
Abstract:
We propose to complete our multi-semester redshift survey of galaxies in 16
groups at 0.8<z<1, selected from ultradeep X-ray observations. Achieving high
completeness in each group, including galaxies an order of magnitude less
massive than are typically included in wide-field surveys, allows us to
answer important questions about how dense environments influence galaxy
evolution. Only with such data is it possible to robustly measure the group
mass, centre and radius, and the group-to-group variations predicted by
simple infall models. Excellent data on half the sample (including >100 new
members) have been obtained. A first paper has been submitted, in which we
report the exciting discovery of a large population of confirmed group
members "caught in the act" of transforming from the blue to red sequence. To
conclusively demonstrate that these galaxies are associated with the group
environment, however, requires the completion of the survey (to improve the
statistical significance from 98% to 99.95%). Only with the full sample of 16
groups can we begin to address our main questions, about how this population
(and other properties like galaxy formation efficiency) vary from
group-to-group and perhaps correlate with other group properties, like X-ray
emission.
National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360
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NOAO > Observing Info > Approved Programs > 2011A-0127 |
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