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Nucleosynthesis in Outflows from the Inner Regions of Collapsars

Jason Pruet·Todd Thompson·R. D. Hoffman
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Abstract

We consider nucleosynthesis in outflows originating from the inner regions of viscous accretion disks formed after the collapse of a rotating massive star. We show that wind-like outflows driven by viscous and neutrino heating can efficiently synthesize Fe-group elements moving at near-relativistic velocities. The mass of 56Ni synthesized and the asymptotic velocities attained in our calculations are in accord with those inferred from observations of SN1998bw and SN2003dh. These steady wind-like outflows are generally proton rich, characterized by only modest entropies, and consequently synthesize essentially nothing heavier than the Fe-group elements. We also discuss bubble-like outflows resulting from rapid energy deposition in localized regions near or in the accretion disk. These intermittent ejecta emerge with low electron fraction and are a promising site for the synthesis of the A=130 r-process peak elements.

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Jason Pruet, Todd Thompson, R. D. Hoffman. 2004-01-16. Nucleosynthesis in Outflows from the Inner Regions of Collapsars. https://doi.org/10.1086/382036

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