Formation and evaporation of strangelets during the merger of two compact stars

Abstract

We study the partial fragmentation of a strange quark star into strangelets during the process of merger of two strange quark stars. We discuss the fate of the fragments considering their possible evaporation into nucleons. We show that only a rather small amount of large size strangelets, ejected from the spiral arms in the postmerger, survives a total evaporation into nucleons. In this way we demonstrate that (1) the density of strangelets in the galaxy is too low to trigger the conversion of all neutron stars into strange quark stars, and it allows the coexistence of both types of compact objects; (2) the probability of direct detection of a strangelet is negligible, and therefore its nondetection is compatible with the strange quark matter hypothesis; (3) most of the matter ejected during and after the merger of two strange quark stars evaporates into nucleons, and therefore it can generate a kilonova-like signal.