General Seminars

A New Search for supernova r-process actinides on Earth

by Shawn Bishop (Universität München)

Thursday, 23 February 2017 from to (Europe/Bucharest)
at DFN / TANDEM Seminar Room
The cosmic site wherein the heavy elements from mass 70 up through to the long-lived actinides remains an unsolved mystery in astrophysics. These elements are produced through a process of rapid, successive capture of neutrons on an initial seed abundance of stable nuclei -- the so-called r-process. Competing theoretical hypotheses suggest core collapse supernovae (CCSN) and/or merging binary neutron stars as the site(s) in which these elements are made, but there remains no empirical evidence to conclusively demonstrate either as an r-process site.

Recent findings of 60Fe (half-life 2.6 Myr) on Earth and in lunar regolith show that between 2.6 and 1.7 Myr before the present, our solar system received freshly synthesized material from a CCSN. If CCSN are indeed a site of the r-process, long-lived actinides such as 244Pu and 247Cm could be present in geological reservoirs coincident in time with the 60Fe signal. This talk will give an introductory overview of the status of the 60Fe searches and the present empirical state of the art hints of actinide production in CCSN, from which a description of our new and present r-process actinide search will follow.