1 / 33

Asymmetric Neutrino Reaction in Magnetized Proto-Neutron Stars in Fully Relativistic Approach

Asymmetric Neutrino Reaction in Magnetized Proto-Neutron Stars in Fully Relativistic Approach. Tomoyuki Maruyama BRS, Nihon Univ. (Japan) Toshitaka Kajino NAO & Univ. of Tokyo (Japan) Nobutoshi Yasutake NAO (Japan)

kiefer
Download Presentation

Asymmetric Neutrino Reaction in Magnetized Proto-Neutron Stars in Fully Relativistic Approach

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Asymmetric Neutrino Reaction in Magnetized Proto-Neutron Stars in Fully Relativistic Approach Tomoyuki Maruyama BRS, Nihon Univ. (Japan) Toshitaka KajinoNAO & Univ. of Tokyo (Japan) Nobutoshi Yasutake NAO (Japan) Myung-ki Cheoun Soongs Univ.(Korea) Chung-Yeol Ryu Soongs Univ. (Korea) TM et al., arXiv:1009.0976, Phys. ReV. D (2011) in press 1

  2. §1. Introduction High Density Matter Study ⇒　Exotic Phases : Strange Matter, Ferromagnetism Meson Condensation, Quark matter, CSC, … They may exist inside Neutron Stars (NSs) Observable Information ‥Neutrino Emissions from Proto-NS S.Reddy, M.Prakash and J.M. Lattimer, P.R.D58 #013009 (1998) Influence from Hyperons Λ，∑ Magnetar 1015G in surface 1017-19G inside (?) Magnetic Field　→　Large Asymmetry？ P. Arras and D. Lai, P.R.D60, #043001 (1999) S. Ando, P.R.D68 #063002 (2003) Neutrino Scattering & Absorption in Surface Region

  3. Pulsar Kick

  4. Pulsar Kick CasA A.G.Lyne, D.R.Lomier, Nature 369, 127 (94) Asymmetry of Supernova Explosion kick and translate Pulsar with Kick Velocity: Average … 400km/s， Highest … 1500km/s Explosion Energy ~ 1053 erg (almost Neutrino Emissions) 1% Asymmetry are sufficient to explain the Pulsar Kick http://chandra.harvard.edu/photo/ 2004/casa/casa_xray.jpg Present Work ‥ Neutrino Scattering and Absorption In Hot and Dense Neutron-Star-Matter Estimating Kick Velocity 4

  5. Baryon B & L – Mag. Lepton §2. Formulation Magnetic Field : Weak Interaction e+ B→ e + B : scattering e+ B→ e-+ B’ : absorption

  6. §2-1 Neutron-Star Matter in RMF Approach RMF Lagrangian, N, L, s, , r

  7. EOS of Proto Neutron-Star-Matter Charge Neutral（ ） & Lepton Fraction : YL = 0.4 7 PM1-L1 T.M, H. Shin, H. Fujii, & T. Tatsumi, PTP. 102, P809

  8. §2-2 Dirac Equation under Magnetic Fields Magnetic Part of Lagrangian Dirac Eq. NB << εF (Chem. Pot) →Bcan be treated perturbatively Landau Level can be ignored ~1017 G

  9. Dirac Spinor Spin Vector

  10. Fermi Distribution Momentum Distribution of Major Part is deformed as oblate

  11. Perturbative Treatment The Cross-Section of Lepton-Baryon Scattering Noraml Part Magnetic Part

  12. Spin-indep. part Spin-dep. Part

  13. 3% difference §3 Results

  14. Magnetic parts of Cross-Sections Scat. Increasing  to Arctic Dir. Absorp. 14

  15. Elements of Absorption Cross-Sections 15 Contribution from Λ is small

  16. §4 Neutrino Absorption in Proto Neutron Star Equib. Part Non-Equib. Part Neutrino Phase Space Distribution Function Neutrino Propagation ⇒　BoltzmannEq. Solution ⇒

  17. θ \ Neutrino Propagation • Neutrinos • propagate on the straight lines • 2) Neutrino are created and absorbed at all positions on the lines • Mean-Free • path • : σab/V

  18. Baryon density in Proto-Neutron Star M = 1.68Msolar YL= 0.4 Calculating Neutrino Propagation above rB = r0

  19. Mean-Free Pathwhen B =0

  20. Angular Dependence of Emitted Neutrino Direction of Emitted Neutrino

  21. p, n p, n,  p, n p, n,  Kick Velocity T = 20 MeV T = 30 MeV Assuming Neutrino Energy ~3×1053 erg D.Lai & Y.Z.Qian, Astrophys.J. 495 (1998) L103 21

  22. EOS of Neutron-Star-Matter with p, n Λ in RMF Appraoch • Cross-Sections of Neutrino Scattering and Absorption under Strong Magnetic Field, calculated in Perturbative Way • Neutrinos are More Scattered and Less Absorbed in Direction Parallel to Magnetic Field 　　　⇒　More Neutrinos are Emitted in Arctic Area Scattering 1.7 % Absorption 2.2 % at ρB=3ρ0 and T = 20 MeV 　⇒　Convection, Pulsar-Kick 22 §5Summary

  23. Estimating Pulsar Kick in Proto-Neutron-Star with Strong Magnetic Field B = 2× 1017G 　⇒ Perturbative Calculations Vkick = 300 km/s ( p,n ) , 290 km/s (p,n,Λ） at T = 20 MeV = 180 km/s ( p,n ) , 77 km/s (p,n,Λ） at T = 30 MeV Antarctic Direction 400 km/s (Observed）, 280km/s (Lai & Qian) Future Plans Fixed Temp. ⇒　Constant Entropy Exact Solution of Dirac Eq. Low Density Contribution is dominant 　 →　 Landau Level at least for Electron Spin-Spin interaction Poloidal Mag. Field ⇒Troidal Mag. Field 23

  24. Birth of Proto-neutron Star 24 24

  25. Structure of compact stars… 25 By D.Page nucleon pasta quark-hadron pasta 25

  26. Temperature & lepton fractionin proto-neutron stars 26 by A.Burrows et al. (1986) T = 40  5 MeV, YL = 0.40.05

  27. Dirac Equation with Magnetic Fields

  28. Dirac Spinor under the Magnetic Field

  29. Stability of Magnetic Field in Compact Objects (Braithwaite & Spruit 2004) Toroidal Magnetic Field is stable !!

  30. EOS of PM1-1

  31. EOS of Neutron-Star-Matter with p, n Λ in RMF Appraoch • Cross-Sections of Neutrino Scattering and Absorption under Strong Magnetic Field, calculated in Perturbative Way • Neutrinos are More Scattered and Less Absorbed in Direction Parallel to Magnetic Field 　　　⇒　More Neutrinos are Emitted in Arctic Area Scattering 1.7 % Absorption 2.2 % at ρB=3ρ0 and T = 20 MeV 　⇒　Convection, Pulsar-Kick §4 Summary 31

  32. Magnetic Parts of Scattering Cross-Sections 32

  33. Magnetic Parts of Absorption Cross-Sections 33 less absorp. Aroundθi=0

More Related