^1,2,8Thomas C. L. Trueman,^1,3,4,8Benoit Côté,^1,8Andrés Yagüe López,^1,8Jacqueline den Hartogh,^1,2,4,8Marco Pignatari,^1,5Benjámin Soós,^6,7Amanda I. Karakas,^1,5,6Maria Lugaro
The Astrophysical Journal 924, 10 Open Access Link to Article [DOI 10.3847/1538-4357/ac31b0]
¹Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Eötvös Loránd Research Network, Konkoly Thege Miklós út 15-17, H-1121 Budapest, Hungary; thomas.trueman@csfk.mta.hu
²E.A. Milne Centre for Astrophysics, Department of Physics & Mathematics, University of Hull, HU6 7RX, UK
³Department of Physics and Astronomy, University of Victoria, Victoria, BC, V8W 2Y2, Canada
⁴Joint Institute for Nuclear Astrophysics—Center for the Evolution of the Elements, USA
⁵ELTE Eötvös Loránd University, Institute of Physics, Budapest 1117, Pázmány Péter sétány 1/A, Hungary
⁶School of Physics and Astronomy, Monash University, VIC 3800, Australia
⁷ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), Australia
⁸NuGrid Collaboration http://nugridstars.org.

Analysis of inclusions in primitive meteorites reveals that several short-lived radionuclides (SLRs) with half-lives of 0.1–100 Myr existed in the early solar system (ESS). We investigate the ESS origin of ¹⁰⁷Pd, ¹³⁵Cs, and ¹⁸²Hf, which are produced by slow neutron captures (the s-process) in asymptotic giant branch (AGB) stars. We modeled the Galactic abundances of these SLRs using the OMEGA+ galactic chemical evolution (GCE) code and two sets of mass- and metallicity-dependent AGB nucleosynthesis yields (Monash and FRUITY). Depending on the ratio of the mean-life τ of the SLR to the average length of time between the formations of AGB progenitors γ, we calculate timescales relevant for the birth of the Sun. If τ/γ ≳ 2, we predict self-consistent isolation times between 9 and 26 Myr by decaying the GCE predicted ¹⁰⁷Pd/¹⁰⁸Pd, ¹³⁵Cs/¹³³Cs, and ¹⁸²Hf/¹⁸⁰Hf ratios to their respective ESS ratios. The predicted ¹⁰⁷Pd/¹⁸²Hf ratio indicates that our GCE models are missing 9%–73% of ¹⁰⁷Pd and ¹⁰⁸Pd in the ESS. This missing component may have come from AGB stars of higher metallicity than those that contributed to the ESS in our GCE code. If τ/γ ≲ 0.3, we calculate instead the time (T_LE) from the last nucleosynthesis event that added the SLRs into the presolar matter to the formation of the oldest solids in the ESS. For the 2 M_⊙, Z = 0.01 Monash model we find a self-consistent solution of T_LE = 25.5 Myr.