Chemical Abundances and the Formation and Evolution of the Galactic Bulge

Johnson Christian I, Bloomington IN

Investigators

Abstract

Dr. Christian Johnson is awarded an NSF Astronomy and Astrophysics Postdoctoral Fellowship to carry out a program of research and education at the University of California, Los Angeles. Dr. Johnson will increase dramatically the number of spectroscopic observations of red giant branch (RGB) stars in the Galactic bulge along both minor axis and off-axis fields. This program will for the first time extend the determination of chemical abundances to light odd-Z elements and heavy neutron-capture elements in a sample of ~1,000 bulge giants. These data will be combined with the results of Dr. Johnson's dissertation work, a comprehensive chemical analysis of ~1,000 RGB stars in Omega Centauri, to provide insight into the chemical evolution of two independent "spheroidal" systems exhibiting signs of significant self-enrichment but that span a metallicity range of nearly a factor of 1,000. Dr. Johnson will also develop a spectrum synthesis webtool designed to help make stellar abundance work more accessible to the general public, undergraduate non-science majors, and advanced undergraduates. The webtool is intended to be a guided tutorial that allows students and the general public to actively participate in determining the chemical composition of stars in the context of learning about stellar evolution and nucleosynthesis. Dr. Johnson will develop activities associated with the webtool that are appropriate for use in both non-science major and advanced undergraduate classes.