Signatures of deconfined quark phases in binary neutron star mergers

We investigate QCD phase transitions in the context of binary neutron star (BNS) mergers. Comparing numerical relativity simulations with equations of state (EOS) that model respectively hadronic matter and a first-order phase transition to quarks, we find that the latter causes an earlier collapse of the merger remnant to a black hole. The phase transition is imprinted on the postmerger gravitational wave (GW) signal duration, amplitude, and peak frequency and does not cause significant deviations from quasi-universal relations for the postmerger GW peak frequency. Hence the postmerger GW peak frequency alone is not sufficient to conclusively exclude or confirm the presence of a phase transition. We also study the impact of the phase transition on dynamical ejecta, remnant accretion disk masses, r-process nucleosynthetic yields, and associated electromagnetic (EM) counterparts. The most robust feature is the non-thermal afterglow caused by the interaction of the fastest component of the dynamical ejecta and the interstellar medium, which is systematically boosted in binaries with phase transition as a consequence of the more violent merger they experience.