Nucleosynthesis of r-Process Elements by Jittering Jets in Core-Collapse Supernovae

TL;DR

This study models nucleosynthesis in the hot bubble of jittering-jet supernovae, finding it can produce significant r-process elements, with results slightly exceeding observed amounts, suggesting more detailed models could improve accuracy.

Contribution

It introduces a simplified model of nucleosynthesis in jittering-jet supernovae, demonstrating the potential for substantial r-process element formation in this scenario.

Findings

Produced several times 10^-4 solar masses of r-process elements

Model results slightly exceed observational estimates

Suggests more realistic models could align better with observations

Abstract

We calculate the nucleosynthesis inside the hot bubble formed in the jittering-jets model for core collapse supernovae (CCSNe) explosions, and find the formation of several times 10^-4 M_\odot of r-process elements. In the jittering-jets model fast jets launched from a stochastic accretion disk around the newly formed neutron star are shocked at several thousands km, and form hot high-pressure bubbles. These bubbles merge to form a large bubble that explode the star. In the current study we assume a spherically symmetric homogenous bubble, and follow its evolution for about one second during which nuclear reactions take place. The jets last for about one second, their velocity is v_j=0.5c, and their total energy is 10^51 erg. We use jets' neutron enrichment independent on time, and follow the nuclear reactions to the formation of the seed nuclei up to $Z \leq 50$, on which more neutrons will be absorbed to form the r-process elements. Based on the mass of the seed nuclei we find the r-process element mass in our idealized model to be several times 10^-4 M_\odot, which is slightly larger than the value deduced from observations. More realistic calculations that relax the assumptions of a homogenous bubble and constant jets composition might lead to agreement with observations.