Explosive Nucleosynthesis from GRB and Hypernova Progenitors: Direct Collapse versus Fallback

Abstract

The collapsar engine behind long-duration gamma-ray bursts extracts the energy released from the rapid accretion of a collapsing star onto a stellar-massed black hole. In a collapsing star, this black hole can form in two ways: the direct collapse of the stellar core into a black hole and the delayed collapse of a black hole caused by fallback in a weak supernova explosion. In the case of a delayed-collapse black hole, the strong collapsar-driven explosion overtakes the weak supernova explosion before shock breakout, and it is very difficult to distinguish this black hole formation scenario from the direct collapse scenario. However, the delayed-collapse mechanism, with its double explosion, produces explosive nucleosynthetic yields that are very different from the direct collapse scenario. We present 1-dimensional studies of the nucleosynthetic yields from both black hole formation scenarios, deriving differences and trends in their nucleosynthetic yields.

47 pages, submitted to ApJ

References in corpus (1)

• Supernova Fallback: A Possible Site for the r-Process

Cited by in corpus (9)

• No supernovae associated with two long-duration gamma ray bursts
• Spatially resolved properties of the GRB 060505 host: implications for the nature of the progenitor
• Numerical Study on GRB-Jet Formation in Collapsars
• The Evolution of Oxygen and Magnesium in the Bulge and Disk of the Milky Way
• A case of mistaken identity? GRB 060912A and the nature of the long -- short GRB divide
• The Spectral Lag of GRB060505: A Likely Member of the Long Duration Class
• Light Curve Calculations of Supernovae from Fallback Gamma-Ray Bursts
• OB Associations, Wolf-Rayet Stars, and the Origin of Galactic Cosmic Rays
• No supernovae detected in two long-duration Gamma-Ray Bursts