2024 journal article

Thallium-208: A Beacon of<i> In</i><i> Situ</i> Neutron Capture Nucleosynthesis

PHYSICAL REVIEW LETTERS, 132(5).

Source: Web Of Science
Added: April 15, 2024

We demonstrate that the well-known 2.6 MeV gamma-ray emission line from thallium-208 could serve as a real-time indicator of astrophysical heavy element production, with both rapid ($r$) and intermediate ($i$) neutron capture processes capable of its synthesis. We consider the $r$ process in a Galactic neutron star merger and show Tl-208 to be detectable from $\ensuremath{\sim}12$ hours to $\ensuremath{\sim}\mathrm{ten}$ days, and again $\ensuremath{\sim}1--20\text{ }\text{ }\mathrm{years}$ postevent. Detection of Tl-208 represents the only identified prospect for a direct signal of lead production (implying gold synthesis), arguing for the importance of future MeV telescope missions which aim to detect Galactic events but may also be able to reach some nearby galaxies in the Local Group.