Date: Wednesday, February 17, 2016
Speaker: Dr. Nan Liu, DTM, Carnegie Institution for Science
Topic: Neutron-capture Processes in Stars: Theories, Stellar Sites, and Implications from Presolar Grain Studies
Time and Location: 1:00 PM, with Q&A to follow; in a 1st floor conference room at the American Center for Physics (www.acp.org), 1 Physics Ellipse, College Park, MD - off River Rd. Between Kenilworth Ave. and Paint Branch Parkway.
Abstract: Heavy elements beyond iron are mainly produced through slow- (s-) and rapid- (r-) neutron-capture processes in different types of stars. On the other hand, presolar grains are pieces of stardust that are found in primitive meteorites and interplanetary dust particles, and recorded nucleosynthetic processes that occurred in their parent stars. Laboratory studies of presolar grains thus provide an unparalleled opportunity to understand these nucleosynthetic processes and also circumstellar condensation conditions in different stellar environments. We discuss here the state of the art and open issues in s- and r-processes. In particular, we overview constraints from multi-element isotopic studies of presolar grains on the stellar origin and isotopic signatures of s- and r-processes.
Biography: Nan Liu received her Ph. D. in Cosmochemistry from the University of Chicago in 2014 and received an undergraduate degree in Environmental Engineering from the University of Science and Technology in 2009. Upon completing her Ph. D., she joined DTM at Carnegie Institution for Science as a postdoc research associate. Her research interests focus on isotopic and structural studies of presolar grains by applying a suite of advanced micro-analytical techniques to understand their stellar origins, nucleosynthetic processes in their parent stars and condensation formation processes in stellar environments.