NOAO > Observing Info > Approved Programs > 2012B-0209
|
NOAO > Observing Info > Approved Programs > 2012B-0209 |
|
PI: Beth Willman, Haverford College, bwillman@haverford.edu
Address: Astronomy Department, 370 Lancaster Avenue, Haverford, PA 19041, USA
CoI: Andrew West, Boston University
Title: Investigating Overdensities of Cool Stars at the Edge of the Milky Way
Abstract:
We propose to use Gemini/GNIRS to observe stars belonging to four
localized overdensities of cool stars in the Milky Way. The proposed
spectroscopic program will determine whether the stars in the
overdensities are dwarfs or giants, and will provide their radial
velocities. If these overdensities are composed of cool giant stars,
then they reside at outer halo (200 - 600 kpc) distances with physical
sizes of 500 pc - 1 kpc, consistent with them being dwarf galaxies (or
the remnants thereof). If these overdensities are composed of cool
dwarf stars, then they reside at nearby (500 pc - 2 kpc) distances with
physical sizes of a few parsec, consistent with them being low surface
brightness star clusters, or the remnants thereof. Independent of
whether these previously unseen structures are composed of dwarf or
giant stars, their presence and origin may have far-reaching
ramifications for the history and evolution of the Milky Way.
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 > 2012B-0209 |
|