Rapidly rotating axisymmetric neutron stars with quark cores
arXiv:1111.4617 · doi:10.1016/j.astropartphys.2012.04.005
Abstract
We present a systematic study of the properties of pure hadronic and hybrid compact stars. The nuclear equation of state (EoS) for beta-equilibrated neutron star matter was obtained using density dependent effective nucleon-nucleon interaction which satisfies the constraints from the observed flow data from heavy-ion collisions. The energy density of quark matter is lower than that of this nuclear EoS at higher densities implying the possibility of transition to quark matter inside the core. We solve the Einstein's equations for rotating stars using pure nuclear matter and quark core. The beta- equilibrated neutron star matter with a thin crust is able to describe highly massive compact stars but find that the nuclear to quark matter deconfinement transition inside neutron stars causes reduction in their masses. Recent observations of the binary millisecond pulsar J1614-2230 by P. B. Demorest et al. [1] suggest that the masses lie within 1.97\pm0.04 M\odot where M\odot is the solar mass. In conformity with recent observations, pure nucleonic EoS determines that the maximum mass of NS rotating with frequency below r-mode instability is ~1.95 M\odot with radius ~10 kilometers. Although compact stars with quark cores rotating with Kepler's frequency have masses up to ~2 M\odot, but if the maximum frequency is limited by the r-mode instability, the maximum mass ~1.7 M\odot turns out to be lower than the observed mass of 1.97\pm0.04 M\odot, by far the highest yet measured with such certainty, implying exclusion of quark cores for such massive pulsars.
12 pages including 6 figures
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Cited by in corpus (7)
- Stability of the -equilibrated dense matter and core-crust transition in neutron stars
- Gravitational waves from isolated neutron stars: mass dependence of r-mode instability
- Core-crust transition and crustal fraction of moment of inertia in neutron stars
- From nuclear reactions to compact stars: a unified approach
- Rotating Neutron Stars with the Relativistic Ab Initio Calculations
- Properties of glitching pulsars in the Skyrme-Hartree-Fock framework
- Effective interaction: From nuclear reactions to neutron stars