国立天文台談話会　NAOJ Seminar

場所： 大セミナー室　Large Seminar Room
日時： ２００８年９月１９日（金）１６：００−１７：００
　　　　16:00 - 17:00, Friday, September 19, 2008

Title:
"How and where are the heavy elements synthesized in the Universe?"

Speaker: Prof. Bradley S. Meyer
　Department of Physics and Astronomy
　Clemson University
　Clemson, SC 29634-0978
　U.S.A.

Abstract.
The elements in our Solar System and our Galaxy heavier than iron were
largely synthesized by neutron-capture processes. Roughly half of these
elements were synthesized by the s (or slow) neutron-capture process.
This occurred over Galactic history in helium burning regions in the
cores of massive stars and the shells of pulsing AGB stars. The r (or
rapid) neutron-capture process was responsible for the synthesis of the
other half of the heavy elements. The site for the r process is at
present unknown, though supernovae are often implicated. In this talk,
I will characterize the r-process mechanism in terms of the entropy per
nucleon. I will show that there are three broad ways of getting enough
neutrons per seed nucleus to make the heavy r-process elements, and I
will discuss the implications of this classification for the search for
the r-process site. I will also discuss libnucnet, our freely
available, open-source library of nuclear reaction network codes, and
how it can help researchers study r-process nucleosynthesis.