Constraining the Rapid Neutron-Capture Process with Meteoritic I-129 and Cm-247. (arXiv:2006.04833v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Cote_B/0/1/0/all/0/1">Benoit Côté</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Eichler_M/0/1/0/all/0/1">Marius Eichler</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Yague_A/0/1/0/all/0/1">Andrés Yagüe</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vassh_N/0/1/0/all/0/1">Nicole Vassh</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mumpower_M/0/1/0/all/0/1">Matthew R. Mumpower</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vilagos_B/0/1/0/all/0/1">Blanka Világos</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Soos_B/0/1/0/all/0/1">Benjámin Soós</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Arcones_A/0/1/0/all/0/1">Almudena Arcones</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sprouse_T/0/1/0/all/0/1">Trevor M. Sprouse</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Surman_R/0/1/0/all/0/1">Rebecca Surman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pignatari_M/0/1/0/all/0/1">Marco Pignatari</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wehmeyer_B/0/1/0/all/0/1">Benjamin Wehmeyer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rauscher_T/0/1/0/all/0/1">Thomas Rauscher</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lugaro_M/0/1/0/all/0/1">Maria Lugaro</a>
Meteoritic analysis demonstrates that radioactive nuclei heavier than iron
were present in the early Solar System. Among them, $^{129}$I and $^{247}$Cm
both have a rapid neutron-capture process ($r$ process) origin and decay on the
same timescale ($simeq$ 15.6 Myr). We show that the $^{129}$I/$^{247}$Cm
abundance ratio in the early Solar System (438$pm$184) is immune to galactic
evolution uncertainties and represents the first direct observational
constraint for the properties of the last $r$-process event that polluted the
pre-solar nebula. We investigate the physical conditions of this event using
nucleosynthesis calculations and demonstrate that moderately neutron-rich
ejecta can produce the observed ratio. We conclude that a dominant contribution
by exceedingly neutron-rich ejecta is highly disfavoured.
Meteoritic analysis demonstrates that radioactive nuclei heavier than iron
were present in the early Solar System. Among them, $^{129}$I and $^{247}$Cm
both have a rapid neutron-capture process ($r$ process) origin and decay on the
same timescale ($simeq$ 15.6 Myr). We show that the $^{129}$I/$^{247}$Cm
abundance ratio in the early Solar System (438$pm$184) is immune to galactic
evolution uncertainties and represents the first direct observational
constraint for the properties of the last $r$-process event that polluted the
pre-solar nebula. We investigate the physical conditions of this event using
nucleosynthesis calculations and demonstrate that moderately neutron-rich
ejecta can produce the observed ratio. We conclude that a dominant contribution
by exceedingly neutron-rich ejecta is highly disfavoured.
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