Realistic nucleon force and X-ray observations of neutron stars

Transcription

1 Realistic nucleon force and X-ray observations of neutron stars Pawe l Haensel haensel@camk.edu.pl New perspectives on neutron star interiors ECT*, Trento, Italy, October Pawe l Haensel (CAMK) Nucleon force and X-ray observations of NS October th, /

2 The team Morgane Fortin, Pawel Haensel, Julian L. Zdunik (CAMK Warsaw) Gabriele Taranto, Fiorella Burgio, Hans-Joseph Schulze (INFN, Catania) Bottom line Using realistic NN+NNN obtain EOS for the NS crust and core, superfluid gaps n, p, effective masses m n, m p, neutrino emissivity Q ν, heat capacity c V. Then add heat conductivity, and deep crustal heating (Q DCH ) in accreting NS. Calculate models of cooling isolated NS and thermal states of transiently accreting NS between accretion episodes. Compare fixed NS-mass curves with X-ray observations of isolated NS and NS in X-ray transients in quiescence and use this to constrain uncertainties in superfluid gaps. Pawe l Haensel (CAMK) Nucleon force and X-ray observations of NS October th, /

3 Our EOS etc. Realistic non-relativistic NN: v ij - AV, NNN: V ijk - UIX P, ε (MeV fm ) x M (M ) n B, n c (fm ) x ε P p µ Normal nucleons - Brueckner-Hartree-Fock (BHF) with continuous U j Nuclear matter n b = n n + n p, x p = n p /n b v ij V ij = v ij + ṽ ij BHF with V ij yields E(n n, n p ), U n, U p, e j = ɛ j + U j Saturation parameters: n s =. fm, E s =. MeV, E sym =. MeV, K = MeV, L =. MeV Results: EOS, also x p, m j - crucial for Q ν. For x p > x DU =. DUrca open; reached at. fm. DUrca proceeds in M > M DU =. M - looks shocking. Catalyzed crust EOS based on the same interaction calculated using the Energy Density Functional method Sharma et al. Pawe l Haensel (CAMK) Nucleon force and X-ray observations of NS October th, /

4 No superfluidity: s n = s p = red - fully accreted crust; blue - catalyzed (ground-state) crust. Pathological feature: nearly all sources have M M DU =. M DUrca problem log L γ (erg s ) M DU +.. s p = s n = log t (yr). M DU log L γ (erg s ) s p = s n =. M DU. M DU +. log Ṁ (M yr ) INS: - CasA NS, - PSR J+ (in C), - PSR B+ (Crab), - PSR J, - RX J (in PupA), - PSR J, - PSR B, - PSR B (Vela), - XMMU J, - PSR J+, - PSR B+, - PSR B+, - PSR B+ (Geminga), - PSR J, - RX J., - PSR J+ (Morla), - PSR B, - PSR J+, - RX J. SXTq: - IGR +, - XTE J, - XTE J, - XTE J, - SAX J, - SAX J, - XTE J, - XTE, - NGC X, - EXO, - Cen X, - U, - S, - H +, - Terzan, - MXB, - RX J, - NGC X, - SAX J., - M, - Terzan, - U, - Aql X, - U +, - KS. Pawe l Haensel (CAMK) Nucleon force and X-ray observations of NS October th, /

5 Superfluidity T c ( K) ns/ns ps ps.. np np M max n B (fm ). Bardeen-Cooper-Schrieffer (BCS) with V ij. Pairing gaps: crust ns (L =, S = ) core np (J =, S =, L =, ) ps (S =, L = ) The BCS values of n and p based on VLL JS do not contain contribution from nuclear matter polarization [induced interaction] Pawe l Haensel (CAMK) Nucleon force and X-ray observations of NS October th, /

6 Superfluidity: s n, s p =. Fast initial cooling of INS due to the Pair Braking and Formation νν emission when local T crosses T crit log L γ (erg s )... s p =. s n = log t (yr) log L γ (erg s ) s p =. s n =.. log Ṁ (M yr ). INS: - CasA NS, - PSR J+ (in C), - PSR B+ (Crab), - PSR J, - RX J (in PupA), - PSR J, - PSR B, - PSR B (Vela), - XMMU J, - PSR J+, - PSR B+, - PSR B+, - PSR B+ (Geminga), - PSR J, - RX J., - PSR J+ (Morla), - PSR B, - PSR J+, - RX J. SXTq: - IGR +, - XTE J, - XTE J, - XTE J, - SAX J, - SAX J, - XTE J, - XTE, - NGC X, - EXO, - Cen X, - U, - S, - H +, - Terzan, - MXB, - RX J, - NGC X, - SAX J., - M, - Terzan, - U, - Aql X, - U +, - KS. Pawe l Haensel (CAMK) Nucleon force and X-ray observations of NS October th, /

7 Superfluid failures - examples log L γ (erg s ).... s p = s n = log t (yr) log L γ (erg s ) s p = s n = log Ṁ (M yr ).... log L γ (erg s ).. s p = s n = log t (yr) log L γ (erg s ) s p = s n =.. log Ṁ (M yr ) Pawe l Haensel (CAMK) Nucleon force and X-ray observations of NS October th, /

8 Conclusions Durca cores are needed for two lowest luminosity SXTq (known) Mass distribution pathology due to sharp-durca threshold is removed if ps is strong enough (at maximum T p crit = K or more) and Durca threshold density is on the T p crit (n b)-curve descending side (known for INS) Strong sensitivity to m j, more advanced calculations needed (known) T n crit in the core should be one - two orders smaller than T p crit (known). Not easy to get in the BCS approximation within n < n b < n. We used not so fine-tuning imposing s n Pawe l Haensel (CAMK) Nucleon force and X-ray observations of NS October th, /