We investigate the quark deconfinement phase transition in cold (T=0) and hot β-stable hadronic matter. Assuming a first-order phase transition, we calculate and compare the nucleation rate and the nucleation time due to quantum and thermal nucleation mechanisms. We show that above a threshold value of the central pressure a pure hadronic star (HS) (i.e. a compact star with no fraction of deconfined quark matter (QM)) is metastable to the conversion to a quark star (QS) (i.e. a hybrid star or a strange star). This process liberates a huge amount of energy, of the order of 1053 erg, which produces a powerful neutrino burst, likely accompanied by intense gravitational waves emission, and possibly by a second delayed (with respect to the supernova explosion forming the HS) explosion which could be the energy source of a powerful gamma-ray burst (GRB). This stellar conversion process populates the QS branch of compact stars, thus one has in the universe two coexisting families of compact stars: HSs and QSs. We introduce the concept of critical mass Mcr for cold HSs and proto-hadronic stars (PHSs), and the concept of limiting conversion temperature for PHSs. We show that PHSs with a mass M<Mcr could survive the early stages of their evolution without decaying to QSs. Finally, we discuss the possible evolutionary paths of PHSs.
Quark deconfinement in neutron stars and astrophysical implications
BOMBACI, IGNAZIO;LOGOTETA, DOMENICO
2016-01-01
Abstract
We investigate the quark deconfinement phase transition in cold (T=0) and hot β-stable hadronic matter. Assuming a first-order phase transition, we calculate and compare the nucleation rate and the nucleation time due to quantum and thermal nucleation mechanisms. We show that above a threshold value of the central pressure a pure hadronic star (HS) (i.e. a compact star with no fraction of deconfined quark matter (QM)) is metastable to the conversion to a quark star (QS) (i.e. a hybrid star or a strange star). This process liberates a huge amount of energy, of the order of 1053 erg, which produces a powerful neutrino burst, likely accompanied by intense gravitational waves emission, and possibly by a second delayed (with respect to the supernova explosion forming the HS) explosion which could be the energy source of a powerful gamma-ray burst (GRB). This stellar conversion process populates the QS branch of compact stars, thus one has in the universe two coexisting families of compact stars: HSs and QSs. We introduce the concept of critical mass Mcr for cold HSs and proto-hadronic stars (PHSs), and the concept of limiting conversion temperature for PHSs. We show that PHSs with a mass MI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.