Bibcode
Bridges, Terry; Beasley, Mike; Faifer, Favio; Forbes, Duncan; Forte, Juan; Gebhardt, Karl; Hanes, Dave; Norris, Mark; Sharples, Ray; Zepf, Steve
Bibliographical reference
NOAO Proposal ID #2008A-0283
Advertised on:
2
2008
Citations
0
Refereed citations
0
Description
Globular clusters (GCs) provide crucial constraints on galaxy formation
models and structure in the Universe, as well as the amount and
distribution of galactic dark matter (DM). We request time to double the
existing sample of GC velocities for the Virgo elliptical galaxy NGC
4649 from 120 to 250. This increased GC sample will allow the use of the
most general possible 3-integral orbit-based models to determine
simultaneously the NGC 4649 DM halo profile and the GC orbital
anisotropy (for all GCs, and for metal-poor/rich GCs separately),
providing an important check on the X-ray derived potential. Using a
novel approach pioneered by this group, we will also extract kinematics
for the stellar light of NGC 4649 beyond 4 effective radii from the same
MOS exposures used in the GC investigation. This combined GC-stellar
spectroscopic dataset will be a powerful probe of the DM content, GC
orbital anisotropy, and angular momentum of NGC 4649.