NOAO > Observing Info > Approved Programs > 2009B-0222
|
NOAO > Observing Info > Approved Programs > 2009B-0222 |
|
PI: Zeljko Ivezic, University of Washington, ivezic@astro.washington.edu
Address: Department of Astronomy, PO Box 351580, Seattle, WA 98195-1580, USA
CoI: Kathy Vivas, Centro de Investig. de Astronomia (CIDA)
CoI: Branimir Sesar, University of Washington
Title: The Most Distant Sub-structure in the Galactic Halo
Abstract:
Using the multi-epoch SDSS data (Stripe 82), a very significant
overdensity of RR Lyrae stars was recently discovered. This clump has
the record of being the most distant from the Sun discovered to the date
in the Milky Way. Its mean distance is 90 kpc from the Sun. We are
proposing to use Gemini + GMOS to obtain spectra of several of the RR
Lyrae stars in this clump. This would allow us: (i) to confirm that the
sub-structure is coherent in velocity space, and (ii) to investigate its
properties (metallicities and velocity dispersions) and hence, its
origin. The detailed studies of halo sub-structures, such as the one we
are proposing to observe with Gemini, are important to test the
hierarchical models of Galaxy formation.
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 > 2009B-0222 |
|