April 2 , 2008
3pm in Howey Physics Lecture Room 5

 

Sung-Chul Yoon
UCO/ Lick Observatory, Department of Astronomy & Astrophysics
University of California, Santa Cruz

 

"Massive stars, supernovae and long gamma-ray bursts"

 

The role of  massive stars and supernovae in the evolution of the universe cannot be overemphasized.  They provide momentum and ionizing photons into interstellar media, critically affecting the cosmic history of star formation and the evolution of galaxies.  Hydrostatic and explosive nucleosyntheses in massive stars and supernovae produce most heavy elements, allowing for the emergence of planets and life in the universe. Due to their unusual energetics, some supernovae serve as cosmic candles for probing the early universe. In particular, long gamma-ray bursts, the most powerful events since the Big-Bang,  are observable from the redshifts of the first generations of stars. The growing evidence for the connection between long gamma-ray bursts (GRBs) and explosions of massive stars  has thus led to the advent of the so-called GRB cosmology. In this talk, after providing a short introduction to stellar evolution and supernova theory,  I will review recent progress in the study of progenitor stars of supernovae and gamma-ray bursts, and  discuss implications for the future use of GRBs for cosmological studies.