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Thermal Evolution of Rotating neutron Stars and Signal of Quark Deconfinement

Thermal Evolution of Rotating neutron Stars and Signal of Quark Deconfinement. Miao Kang. Henan University, Kaifeng, China. Model of neutron stars(hybrid stars) The energy release of quark deconfinement Thermal evolution of hybrid stars and quark deconfinement signature

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Thermal Evolution of Rotating neutron Stars and Signal of Quark Deconfinement

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  1. Thermal Evolution of Rotating neutron Starsand Signal of Quark Deconfinement Miao Kang Henan University, Kaifeng, China

  2. Model of neutron stars(hybrid stars) The energy release of quark deconfinement Thermal evolution of hybrid stars and quark deconfinement signature Conclusion and Discussion

  3. Model of hybrid stars Maxwell construction (a sharp transition takes place between the two charge-neutral hadron and quark phase) (Baym & Chin ,1976,Phys.Lett.B, 62,241) Gibbs construction (the transition can occur through the formation of a mixed phase of hadron matter and quark matter, total charge neutrality being achieved by a positively charged amount of hadron matter and a negatively charged amount of quark matter) (Glendenning N. K., 1992, Phys. Rev. D, 46,1274)

  4. Model of hybrid stars Gibbs condition at zero temperature between hadron phase and quark phase

  5. Quark matter Composition: u,d,s,e Model: effective mass bag model considering medium effect(MIT) Idea: quasi-particle approximation Parameters: bag constant B, coupling constant g, the current mass of s quark ms (Schertler et al. Nucl.Phys.A(1997)) Equation of state (EOS)

  6. Equation of state (EOS) Hadron matter • Composition: n,p,e, • Model: subnuclear densities: Baym-Pethick-Sutherland(BPS) EOS (Baym,G.,Pethick,C.,Sutherland,P. Astrophys.J,170 299(1971)) nuclear densities: Argonne EOS (Akmal A., Pandharipande V. R., Ravenhall D. G.,Phys.Rev.C58,1804(1998)) • Composition: n,p,e, • Model: subnuclear densities: Baym-Pethick-Sutherland(BPS) EOS (Baym,G.,Pethick,C.,Sutherland,P. Astrophys.J,170 299(1971)) nuclear densities: Argonne EOS (Akmal A., Pandharipande V. R., Ravenhall D. G.,Phys.Rev.C58,1804(1998)) • Composition: n,p,e, • Model: subnuclear densities: Baym-Pethick-Sutherland(BPS) EOS (Baym,G.,Pethick,C.,Sutherland,P. Astrophys.J,170 299(1971)) nuclear densities: Argonne EOS (Akmal A., Pandharipande V. R., Ravenhall D. G.,Phys.Rev.C58,1804(1998)) • Composition: n,p,e, • Model: subnuclear densities: Baym-Pethick-Sutherland(BPS) EOS (Baym,G.,Pethick,C.,Sutherland,P. Astrophys.J,170 299(1971)) nuclear densities: Argonne EOS(APR) (Akmal A., Pandharipande V. R., Ravenhall D. G.,Phys.Rev.C58,1804(1998)) the nucleon interaction with the inclusion of a parameterized three-body force and relativistic boost corrections

  7. B=85,108,136 g=3.0 Ms=150.0MeV Equation of state (EOS)

  8. Static configuration TOV equation (Oppenheimer & Volkoff Phys.Rev,55 374(1939)) Structure evolution of hybrid stars

  9. Structure evolution of hybrid stars Rotation configuration Perturbative Approach (Hartle J. B., 1967, ApJ, 150, 1005) Maximum rotation frequency static B=108 Nucleon direct Urca process Quark deconfinement

  10. Non-linear dissipation (Professor Zheng xiaoping) The deconfine phase transition from hadron matter to quark matter may continuously occurs during spin-down of NSs. The density of any given fluid element increases, changing its equilibrium state. The relaxation toward the new equilibrium appears accordingly if the transition has nonlinear phase structure by Gibbs construction. So the two phases are not quite equilibrium and binding energy is stored that can be released by phase transition. Energy release of deconfinement

  11. Energy release of deconfinement Energy release per baryon The total heat luminosity The simple parameterized form 0.1MeV

  12. Energy release of deconfinement The number of quarks converting into baryons Kang M., Zheng X. P., 2007, MNRAS, 375,1503

  13. Hadron matter: nucleon direct Urca (NDU) nucleon modified Urca(NMU) nucleon bremsstrahlung(NB) Quark matter: quark direct Urca (QDU) quark modifiedUrca (QMU) quark bremsstrahlung(QB) Neutrino emission Glen & Sutherland 1980 Heat capacity Neutrino emission luminosity Surface photon luminosity

  14. Thermal evolution of hybrid stars 1.6 solar mass A quite clear magnetic-field dependence Deconfinement heating can produce a characteristic rise of surface temperature Deconfinement heating dominate the behavior of thermal evolution Low magnetic field (B=10^9G) produces a sharp jump in surface temperature

  15. Thermal evolution of hybrid stars deconfinement heating delay the cooling observational data can be explained well Without DH Magnetic Bm=10^12,10^11 Gauss

  16. Thermal evolution of hybrid stars High temperatures of stars at older ages(>10^9) yrs A period of increase of surface temperature A evidence of existence of deconfinement quark matter? Magnetic Bm=10^9,10^8 Gauss

  17. Explore the signal of quark matter appearing through theoretical simulation of thermal evolution curves of hybrid stars with deconfinement heating. Rise of surface temperature of stars is derived from the deconfinement heating. Rise of surface temperature accompany quark matter appearing It may be a evidence for existence of quark matter, if a heating period is observed for a very old pulsar. Conclusion

  18. The mass range of deconfined signal emerging can be changed with varying of some parameters(bag constant B, coupling constant g). The deconfinement heating rate is different for various stages of stars. This may lead to special effect of short timescale behaviors due to local heat deposit and enhanced neutrino emission. The details of evolution in years is worth discussion in future researches. Discussion

  19. Different bag constant

  20. Thanks!

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