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

Christopher L. Fryer·Patrick A. Young·Aimee L. Hungerford
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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.

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Christopher L. Fryer, Patrick A. Young, Aimee L. Hungerford. 2006-04-21. Explosive Nucleosynthesis from GRB and Hypernova Progenitors: Direct Collapse versus Fallback. https://doi.org/10.1086/506250

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