Binary neutron star (NS) merger is a promising site for the rapid neutron capture nucleosynthesis (r-process). The radioactive decay of newly synthesized elements powers electromagnetic radiation, as called kilonova. The detection of gravitational wave from a NS merger GW170817 and the observation of the associated kilonova AT2017gfo have provided with us the evidence that r-process happens in the NS merger. However, the abundance pattern synthesized in this event, which is important to understand the origin of the r-process elements, is not yet clear. In this talk, Ms. Domoto first introduced an overview and current understanding of kilonova. Then, she discussed her recent findings of elemental features in photospheric spectra of kilonova toward identification of elements.

Reported by Shigehiro Nagataki