Galactic Structure Across the Sky with AAOmega
Abstract
As more photometric, kinematic and metallicity data are accumulated the Galaxy appears to be more complex and we are in danger of missing the wood for the trees. The need for wide-area systematic surveys in well-motivated lines-of-sight is apparent. We have undertaken a survey with the new 2-degree field multi-fibre spectrograph on the AAT, AAOmega, that addresses the scientifically important questions of spatial gradients in structure, kinematics and metallicity, focusing on the thick disk -halo interface. We have obtained radial velocities to better than 10km/s, and metallicities to 0.2 dex, for some 10,000 faint (V 19) F/G dwarf stars in intermediate-latitude fields, across the equatorial stripe covered by SDSS DR4. The data allow the determination of small-scale ( 300pc) and large-scale (several kpc) variations and correlations between kinematics and metallicity. Our results will quantify the relative importances of dissipational (slow settling to equilibrium) and dissipationless (stellar mergers and accretion) physics in the formation of the oldest components of the Galaxy.
- Publication:
-
American Astronomical Society Meeting Abstracts
- Pub Date:
- December 2006
- Bibcode:
- 2006AAS...20917215W