http://arxiv.org/abs/2110.05449
GW170817 has confirmed binary neutron star mergers (BNSMs) as one of the sources of nuclei produced by the rapid neutron capture ($r$) process. However, the details of nucleosynthetic pattern emerging from BNSMs as well as the physical condition of $r$-process remain unknown. Moreover, additional sites for $r$-process that have been proposed cannot be ruled out and may even be needed to explain all the observations related to the evolution of $r$-process elements. The measurement of the abundances of particular short-lived radioactive isotopes (SLRIs) in the early solar system (ESS), that are synthesized almost exclusively by $r$-process, can provide independent clues regarding the nature of $r$-process events that occurred during the formation of the SS. In this work, we study the evolution of $r$-process SLRIs $^{129}$I and $^{247}$Cm as well as the corresponding reference isotopes $^{127}$I and $^{235}$U at the Solar location. We consider up to three different sources that have distinct $^{129}$I/$^{247}$Cm production ratios corresponding to the varied $r$-process conditions in different astrophysical scenarios. In contrast to the results found by Cote et al. (2021), we find that $^{129}$I and $^{247}$Cm in the ESS do not come entirely from one single major event but get additional contributions from at least 2 more minor contributors. This has a dramatic effect on the evolution of the $^{129}$I/$^{247}$Cm ratio, such that the measured ESS value in meteorites may not correspond to that of the “last” major $r$-process event. [abridged]
P. Banerjee, M. Wu and J. K
Tue, 12 Oct 21
73/73
Comments: 15 pages, 5 figures, 7 tables. Comments welcome