Ages, Kinematics, and Chemistry of Stellar Populations

点击翻译按钮获取中文摘要

Ages, Kinematics, and Chemistry of Stellar Populations. The relationships of the Galaxy's stellar populations remain a puzzle. Kinematically biased programs, even with the detailed modeling to be completed during the award period, do justice to hot populations like the Galactic halo but not to cool disk populations. Thus, a program begun in 1991 will be carried to completion in the solar neighborhood wherein Dr. Carney, together with Dr. John Laird at Bowling Green University, will identify several thousand G dwarf stars, then determine accurate radial velocities and metallicities to test the discrete versus continuum models of the thick disk and thin disk populations. The study and use of synthetic spectra will be extended into the infrared in anticipation of future chemistry versus kinematics studies throughout the disk. Recent age estimates of the oldest globular clusters are inconsistent with the expansion ages implied by the popularly favored large Hubble constants, independent of the local mass density parameter. For more accurate ages of globular clusters, more work is required on the abundance of oxygen in halo stars. A test of the halo distance scale will be performed using a maximum likelihood statistical parallax analysis of 500 metal-poor stars. Lithium abundances in single halo stars with a wide range of effective temperature will be derived to probe Big Bang nucleosynthesis.