The Universe emerged from its first three minutes with a composition consisting of hydrogen, deuterium, 3 He, 4 He, and 7 Li. These isotopes constitute the primordial compositions of galaxies. Within galaxies, the synthesis of heavier elements from carbon through uranium is understood to occur during the normal
evolution of stars and in supernova explosions of Types I and II. This history is written in the compositions of the stars and gas in our Galaxy and other galaxies as a function of time (“metallicity”). The contributions both from massive stars (M > 10 solar masses) and associated Type II supernovae and from thermonuclear (Type Ia) supernovae are particularly noteworthy. We review both the nuclear processes by which this occurs and the compositions of the stellar components of our Galaxy as a function of time, and discuss how such observations inform us of the natures and nucleosynthesis products of the earliest stellar populations of galaxies and the Cosmos.
Tuesday, February 14th
Seminar is to be held at 4:00 PM in the conference room
on the second floor of Dearborn Observatory
Refreshments will be served at 3:30
|
