Kavli Affiliate: Li Xin Li
|Summary:The observation of a kilonova AT2017gfo associated with the gravitational wave event GW170817 provides the first strong evidence that neutron star mergers are dominant contributors to the production of heavy $r$-process elements. Radioactive gamma-ray lines emitted from neutron star merger remnants provide a unique probe for investigating the nuclide composition and tracking its evolution. In this work, we studied the gamma-ray line features arising from the radioactive decay of heavy nuclei in the merger remnants based on the $r$-process nuclear reaction network and the astrophysical inputs derived from numerical relativity simulations. The decay chain of $^126_50$Sn ($T_1/2=230$ kyr) $to$ $^126_51$Sb ($T_1/2=12.35$ days) $to$ $^126_52$Te (stable) produces several bright gamma-ray lines with energies of $415$, $667$, and $695$ keV, making it the most promising decay chain during the remnant phase. The photon fluxes of these bright gamma-ray lines reach $sim10^-5$ $γ$ cm$^-2$ s$^-1$ for Galactic merger remnants with ages less than $100$~kyr, which can be detected by the high energy resolution MeV gamma-ray detectors like the MASS mission.| Search Query: arXiv Query: search_query=au:”Li Li-Xin”&id_list=&start=0&max_results=10Read More