Signals of the QCD Phase Transition in Core-Collapse Supernovae

We explore the implications of the QCD phase transition during the postbounce evolution of core-collapse supernovae. Using the MIT bag model for the description of quark matter, we model phase transitions that occur during the early postbounce evolution. This stage of the evolution can be simulated with general relativistic three-flavor Boltzmann neutrino transport. The phase transition produces a second shock wave that triggers a delayed supernova explosion. If such a phase transition happens in a future galactic supernova, its existence and properties should become observable as a second peak in the neutrino signal that is accompanied by significant changes in the energy of the emitted neutrinos. This second neutrino burst is dominated by the emission of antineutrinos because the electron degeneracy is reduced when the second shock passes through the previously neutronized matter.

Figure 1

The onset (thick lines) and the end (thin lines) of the mixed phase from the QCD phase transition from nuclear matter to quark matter using eos1.

Figure 2

Neutrino luminosities (a) and (b) and rms-energies (c) calculated at 500 km radius for a $10M_{\odot }$ progenitor model. The results of the quark EOS eos1 (thin lines) are compared to the results of the pure hadronic EOS [17] (thick lines). A second neutrino burst is clearly visible at $\sim 260\mathrm{ms}$ after the bounce.

Figure 3

Velocity profiles at different times during the postbounce evolution of a $10M_{\odot }$ progenitor model based on eos1, illustrating the development of the explosion through different stages.