NOAO >   Observing Info >   Approved Programs >   2009A-0231

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Proposal Information for 2009A-0231


PI: Renato Dupke, University of Michigan, rdupke@umich.edu
Address: Department of Astronomy, 930 Dennison, 500 Church St., Ann Arbor, MI, 48109-1090, USA

CoI: Claudia Mendes de Oliveira, Universidade de Sao Paulo
CoI: Raimundo Lopes de Oliveira, Universidade de Sao Paulo
CoI: Eli Rykoff, UC Santa Barbara

Title: An extensive study of the Fossil Groups of galaxies

Abstract: Fossil Groups (FGs) present a puzzle to current theories of structure formation. Despite the low number of bright galaxies, their high velocity dispersions and high gas temperatures seem to indicate potential wells deeper than those of normal groups. The measured concentration parameters seem to be very high indicating very early formation epochs, which is in contradiction with the observed lack of cooling cores. We were granted Chandra observations of the first large X-ray sample of (15) bona-fide FGs and we are requesting an optical follow-up to determine precise velocity dispersions of 9 groups. The characterization of this sample will allow us to set significant constraints on the ages and formation mechanisms of these peculiar systems. This proposal represents the joining of two efforts: one group that has been carrying out the largest survey of FGs in the optical (in Brazil) and another group with X-ray expertises carrying out the largest survey in X-rays (in the USA).


National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360



NOAO >   Observing Info >   Approved Programs >   2009A-0231

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