NOAO > Observing Info > Approved Programs > 2011B-0575
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NOAO > Observing Info > Approved Programs > 2011B-0575 |
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PI: Steven Majewski, University of Virginia, srm4n@virginia.edu
Address: Dept. of Astronomy, P.O. Box 400325, Charlottesville, VA 22904-4325, USA
CoI: Kathryn Johnston, Columbia University
CoI: Helio Rocha-Pinto, UFRJ, Observatorio do Valongo, Brazil
CoI: Richard Patterson, University of Virginia
CoI: Allyson Sheffield, Columbia University
CoI: Guillermo Damke, University of Virginia
CoI: Jeffrey Carlin, Rensselaer Polytechnic Institute
CoI: Ricardo Munoz, Yale University, Universidad de Chile
Title: Testing Dynamical Models of Star Cloud Formation with the Tri-And System
Abstract:
This proposal requests time to map the radial velocity structure of
the Triangulum-Andromeda cloud --- one of several amorphous stellar
structures discovered in recent years in the Galactic halo. Models
suggest that, like the more well-known stellar streams, these clouds
could result from the disruption of satellites during the hierarchical
formation of our Galaxy. The models have definite predictions that
differentiate clouds from streams in: velocity (they should exhibit
strong velocity gradients), origin (their progenitor objects should be
on highly eccentric orbits) and location (the clouds should lie at the
orbital apocenter of the parent satellite). Perhaps the most intriguing
property of clouds is that their debris is expected to have explored a
large a range of radii, and hence should be sensitive to the radial
profile of the Galactic dark matter distribution. However, none of
these clouds in the Milky Way have yet been extensively mapped. Our
program results will be used either to confirm or refute the origin of
these structures as suggested by the models, to guide creation of a new
model made specifically for the Triangulum-Andromeda system, and to
serve as new constraints on the Galactic potential.
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 > 2011B-0575 |
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