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Accepted · first revision · record

Title: Can neutron-star mergers explain r-process elements in the oldest stars?
Plain: Some very old stars already contain r-process elements, yet merging neutron stars need time to spiral together.
Precise: Determine whether merger delay-time distributions (minimum ~10 Myr, $\mathrm{d}N/\mathrm{d}t \sim t^{-1}$) with natal kicks and inhomogeneous mixing reproduce r-process enrichment in ultra-faint dwarf galaxies such as Reticulum II and the decline of $[\mathrm{Eu}/\mathrm{Fe}]$ at $[\mathrm{Fe}/\mathrm{H}] > -1$ in the Galactic disk, or whether a prompt source is required. Answer: yes or no from galactic chemical evolution models.
Settled by: Chemical-evolution models with measured delay times and kicks fit to large samples of Eu abundances in dwarf galaxies and the disk, with and without a prompt source.
Kind: well-posed
Answer type: yes-no
References: (empty)
Literature status: contested
Status note: (empty)
Posed since: (empty)