The formation and evolution of galaxies is one of the outstanding problems in astronomy. Researchers have studied the Milky Way from observational and theoretical perspectives for a long time, but many details of the formation of Galactic stellar populations and their chemical evolution are still murky. Detailed chemical abundance analysis combined with kinematic and age information can help distinguish between stellar populations and population formation models. Extra-galactic studies often use globular clusters as representatives of the stellar populations, since clusters are massive and their stars (often) homogeneous in age and chemical content.
In the Milky Way, globular clusters are divided as the field star populations are, and associated with the Galactic disk, bulge or halo. These divisions are based on both metallicity and kinematical criteria. While the halo clusters are numerous and well studied, only a few metal-rich disk/bulge clusters have been studied recently. We propose to gather high quality high-resolution spectra of giant stars in selected metal-rich globular clusters and analyse their chemical patterns. This, in combination with new photometry and age estimates, can reveal whether these clusters share a formation history with field stars at similar metallicities.
The project will be carried out in collaboration with astronomers who have amassed a substantial field star comparison sample, and work can begin immediately. Cluster data can be obtained from the excellent spectrograph on the Very Large Telescope, which produces high quality data very efficiently. We can then conduct a self-consistent differential study with great precision. As chemical differences between the various disk populations are subtle, it is important to control systematic error in this way. This project also provides collaborative opportunities for the Lund and Texas groups, whose expertise in stellar populations and nucleo-synthesis are complementary.
Call for proposal
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