SIMBAD references

We investigate the significance of isomers on a kilonova associated with neutron star mergers (NSMs) for the first time. We calculate the evolution of abundances and energy generation rates ({dot}[?] _nuc) of ejecta from NSMs, taking into account β- decay through isomers. We find that for ejecta with electron fraction (Ye) of 0.2-0.3, {dot}[?] _nuc is appreciably changed from those without isomers, due to the large change in timing of β- decay through the isomeric states (ISs) of 123,125,127Sn and 128Sb. In particular, the effects of the isomers on {dot}[?] _nuc are prominent for ejecta of Ye ∼ 0.25, which could emit a fraction of an early, blue component of a kilonova observed in GW170817. When the excitation from a ground state to its IS is important, the isomers of 129Sb and 129, 131Te also cause additional and appreciable change in {dot}[?] _nuc. Furthermore, we demonstrate that larger amounts of lanthanide-free ejecta result in a better fit of an observed light curve of the kilonova in GW170817 if the isomers are taken into account.