Open cluster s- and r-process abundances and the evolution of the Milky Way disk

Jacobson Heather, Bloomington IN

Investigators

Abstract

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Dr. Heather Jacobson is awarded an NSF Astronomy and Astrophysics Postdoctoral Fellowship to carry out a program of research and education at Michigan State University. Open star clusters, whose ages and distances can be reliably determined, have long been used to probe the chemical evolution of the Milky Way disk. Until now, open cluster chemical abundance studies have focused on iron and the light and alpha-elements, and the exact nature of the transition from the inner disk to the outer disk and of the outer disk itself is still unclear. Dr. Jacobson will determine detailed abundances of s- and r-process elements via high-resolution spectroscopy for a large sample of open clusters in the Milky Way disk, with emphasis on clusters in the transition region and in the outer disk. S- and r-process elements such as barium and europium are formed via neutron-capture on to iron-peak nuclei inside low-mass evolved asymptotic-giant-branch stars or in Type II supernovae. The abundance distributions of these elements, along with those previously studied, will provide more clues to the chemical enrichment history of the Galaxy at different locations in the disk, and whether or not the outer disk has a distinct evolutionary history than the inner disk. Dr. Jacobson will also design a new introductory astronomy class for non-science majors based upon the "Astronomy Picture of the Day" website and other material geared towards the general public. A significant component to the course will be to read and discuss how course topics are represented by the news media to the general public. The goals of the course are not only to improve students' knowledge of astronomy, but to make them scientifically literate so they can read and identify where science articles may be correct, incomplete or misleading. The ultimate goal will be to give future leaders and policy-makers the scientific background and tools they need to make informed decisions about science education and policy.