1. Moment of Inertia of Neutron Star Crust Calculations vs. Glitches Observations Joanna Porębska Jagiellonian University – prof. Marek Kutschera & Nuclear Physics Institute (Polish Academy of Sciences) - collaboration with dr Sebastian Kubis, Cracow Dense Matter in HIC and Astrophysics, Dubna, 18.07.2008

2. General structure of NS core crust

3. Equations of Internal Structure 3) Equation of State (EoS) 1)Tolman-Oppenheimer-Volkoff (TOV), r Sch ~4km → GR 2) mass=f(r)

4. EoS… in more details only some analytical solutions energy density (APR model) energy per particle (nucleon) derivatives of E,ε masses

5. EoS… density & pressure density and pressure - full expressions leptons

6. Neutrality & β equilibrium β equilibrium electrical neutrality

7. Compressibility K  stability considerations V(n) - isoscalar potential E s (n) – symmetry energy corresponding to the interactions isovector channel

8. EoS again... two regimes APR - Akmal, Pandharipande & Ravenhall (npe  ) SLy - Skyrme, Lion SLyAPR low densityhigh density n limit 0.01 n cc 0.08 n sat 0.16 n max ~15 n sat n baryon density saturation of nuclear interactions

9. Calculations the fourh-order Runge-Kutta integration method (rk4) output: Moment of Inertia (Pethick, Ravenhall formulae) Results…

10. Glitches staff What are they…? Glitch - sudden spin-up of pulsar produced by angular momentum transfer from the superfluid component of the stellar interior to the normal crust What do they say about crust Moment of Inertia? … frequency jump spin-down rate jump

11. I crust from glitches I c - solid crust + tightly coupled rest (90% of all the star) I res - angular mom. reservoir A - pulsar activity parameter G - coupling parameter – minimum fraction of the star mom. of in. that stores angular momentum and imparts it to the crust in glitches Alpar ’93 >2.4%, Datta&Alpar ’93 >3.4% for 1.4M Θ

12. Conclusions.. Hybrid approach (calculative-observational) Verification/falsification Quite nice confirmation.. Still under construction Considerations.. to be continued

13. References M.Camenzind, Compact Objects in Astrophysics (WD, NS & BH) (Springer-Verlag, Berlin Heidelberg, 2007) N.K.Glendenning, Compact Stars: Nuclear Physics, Particle Physics and GR (Springer-Verlag, New York, 1997) P.Haensel, A.Y.Potekhin, D.G.Yakovlev, Neutron Stars 1: Equation of State and Structure (Springer, 2007) S.Kubis, Phys. Rev. C 76, 025801(2007) C.P.Lorenz, D.G.Ravenhall, C.J.Pethick Phys. Rev. Lett. 70, 4 (1993) B.Link, R.I.Epstein, J.M.Lattimer, Phys. Rev. Lett. 83, 17 (1999) D.G.Ravenhall, C.J.Pethick, ApJ 424:846-851 (1994)

14. Dziękuję bardzo Thank you