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Exploring interior of neutron star through neutron star cooling

Exploring interior of neutron star through neutron star cooling. T. Tatsumi (Kyoto U.). Introduction Thermal evolution of neutron stars -Basic concepts of cooling curve of neutron stars III. Neutrino luminosity as a probe of new form of matter inside neutron stars

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Exploring interior of neutron star through neutron star cooling

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  1. Exploring interior of neutron star through neutron star cooling T. Tatsumi (Kyoto U.) Introduction Thermal evolution of neutron stars -Basic concepts of cooling curve of neutron stars III. Neutrino luminosity as a probe of new form of matter inside neutron stars IV Observation of Cas A and nucleon superfluidity V Summary and concluding remarks

  2. I. Introduction crust core Structure of neutron stars

  3. EOS (Equation of state) gives M-R relation (Bulk properties of neutron stars) Cooling curve (Thermal evolution) (Magnetic evolution) Can microphysics understand or explain these observables ? ・There have been measured various observables about neutron stars , and great progress in observational technique. ・Unfortunately, most of phenomena occurs near the surface , and can provide us with indirect information about interiors of neutron stars, especially the core region, except their bulk properties. ・Among them neutron star cooling can give direct information of properties of matter at high densities through neutrino emission.

  4. Magnetars(1985) Dipole radiation

  5. R.A. Hulse and J.H. Taylor, Ap J. !95(1975) L51. J. Antoniadis et al. Science 340 (2013) 6131 (P. B. Demorest, Nature 467, 1081, 2010) J. Lattimer, arXiv:1305.3510

  6. (P. B. Demorest, Nature 467, 1081, 2010)

  7. Comparison with observation D.Page, arXiv:1206.5011 Crab Vela Cas A 3C 58 Cas A Young pulsars

  8. II. Thermal evolution of neutron stars

  9. (+H)

  10. (crust)

  11. Cold catalyzed matter: 　　・chemical equilibrium 　　・charge neutrality Ex) n,p,e matter For free particles triangle condition: Direct URCA (b decay) cycle is strongly suppressed in normal neutron star matter. e n Modified URCA N N

  12. Basic Cooling: neutrino vs photon cooling eras Neutrino Cooling era: Ln>> Lg Photon Cooling era: Ln << Lg

  13. “Standard” scenario Neutrino cooling Relaxation Photon cooling Nosuperfluid MURCA (slow cooling) 3C58 D.G. Yakovlev and C.J. Pethick, Ann. Rev. Astron. Astrophys. 42 (2004) 169.

  14. III. Neutrino luminosity as a probe of new form of matter inside neutron stars Fast cooling Exotic cooling New form of matter Standard cooling Modified URCA+photon (+superfluidity) Slow cooling for 3C58, Vela

  15. Boson Condensate Hyperonic Matter Λ Quark Matter K Σ d π u s s u Strange Quark Matter d New form of matter or Various phases inside neutron stars

  16. Everywhere in neutron star cores. Most important in low-mass stars. Modified Urca process Brems- strahlung Inner cores of massive neutron stars: Nucleons, hyperons Pion condensates Kaon condensates Quark matter

  17. Fast cooling vs slow cooling Exotic cooling – Impact of 3C58 3C58 is the remnant of a supernova observed in the year 1181 by Chinese and Japanese astronomers. A long look by Chandra shows that the central pulsar - a rapidly rotating neutron star formed in the supernova event - is surrounded by a bright torus of X-ray emission. An X-ray jet erupts in both directions from the center of the torus, and extends over a distance of a few light years. Further out, an intricate web of X-ray loops can be seen. (NASA,2004) 3C58

  18. CONCLUSIONS • about the • THEORY • EOS quite well determined • The mass of the star has little impact • The dominant neutrino emission process • is from the formation and breaking of • Cooper pairs from the neutron 3P2 gap • (unless this gap is very small) • Possibility of the presence of light • elements in the envelope allows to • accommodate a range of Te at a given age h’ e S. Tsuruta et al., Ap.J. 571 (2002) L143. n h

  19. IV. Observation of Cas Aand nucleon superfluidity W.C.G. Ho et al, Nature 462 (2009) 71 NASA K.G.Elshamouty et al., arXiV:1306.3387

  20. D.Page, arXiv:1206.5011 Cas A 3C58

  21. Predictions for the NEUTRON1S0 gap Medium polarization effect O(1/3) Important feature: WE DO NOT REALLY KNOW WHAT IT IS Medium polarization effects were expected to increase the 3P2 gap while they probably strongly suppress it.

  22. Cooling of compact starsand superfluidity D. Page et al., astro-ph/0508056 D.G. Yakovlev and C.J. Pethick, Ann. Rev. Astron. Astrophys. 42 (2004) 169. New form of matter ・Enhancement of neutrino luminosity ・Suppression by the pairing

  23. Neutrino cooling era Photon cooling era

  24. Neutrino emission through the formation and breaking of Cooper pairs (PBF) c.f.Quasiparticlerecombination time (life-time) in a superconductor Cooper pair Quasi-particles Flowers, Ruderman & Sutherland, Ap. J. 205 (1976), 541 Voskresenskii & Senatorov, Zh. Eksp. Teor. Fiz. 90 (1986), 1505 [JETP 63 (1986), 885] Voskresenskii & Senatorov, Yad. Fiz. 45 (1987), 657 [Sov. J. Nucl. Phys. 45 (1987), 411] D.G. Yakovlev et al., A&A 343(1999) 650. See also J.R. Schriefer and D.M. Ginsberg, PRL 8 (1962) 207.

  25. Neutral-current weak interaction ex) Singlet pairing (Flowers, Ruderman & Sutherland, Ap. J. 205 (1976), 541) Quasi-particle op. Emissivity (singlet pairing case)

  26. below Tc Emissivity c.f. E.Flowers et al.,ApJ 205(1976)541.

  27. Cooper Pair Neutrino Luminosities vs MURCA and Photons Cas A is around here? Cooper cooling Cas A is around here?

  28. D.Page, arXiv:1206.5011 Cas A 3C58

  29. Comments about neutral current processes:

  30. well known unknown ~1.47 ~ 0.3 Ratio of the reaction rate - Spin content of proton, especially due to ss sea (T.T., T. Takatsuka, R. Tamagaki, PTP 110 (2003) 179.)

  31. V Summary and concluding remarks ・Cooling of neutron stars has provided us with information of high-density matter through the neutrino emission mechanism. ・Surface temperature of some pulsars has already suggested a fast cooling, which may need exotic cooling. ・Recent observation of Cas A may give information of nucleon superfluidity. ・Can we catch an evidence about Quark Matter through cooling of “neutron stars”? ・Simultaneous observation of surface temperature and other observables such as mass, radius … is desired to extract definite conclusions.

  32. 平均場近似とBogoliubov-Vanatin変換

  33. Leptonic tensor: ランダウ・リフシッツ 相対論的量子力学

  34. Vector current only:

  35. BCS 理論ミニマム クーパー対の凝縮状態

  36. Lenard integral [A.Lenard (1953), Landau & Lifshitz] For other application, e.g. muon decay:

  37. D.G. Yakovlev et al., A&A 343(1999) 650 Neutral current (Non-rela.) Fermi’s Golden rule:

  38. (I. Sagert et al., arXiv:0809.4225) II. Thermal evolution of neutron stars (T. Fischer, CSQCDII)

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