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Neutrinos produced by heavy nuclei injected by the pulsars in massive binaries

Neutrinos produced by heavy nuclei injected by the pulsars in massive binaries. Marek Bartosik & W. Bednarek, A. Sierpowska Erice ISCRA 2004. The purpose. Neutrinos from massive binaries e.g. Gaisser & Stanev 1985 Berezinsky et al. 1986. large angles – non eclipsing binaries.

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Neutrinos produced by heavy nuclei injected by the pulsars in massive binaries

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  1. Neutrinos produced by heavy nuclei injected by the pulsars in massive binaries Marek Bartosik & W. Bednarek, A. Sierpowska Erice ISCRA 2004

  2. The purpose • Neutrinos from massive binaries e.g. • Gaisser & Stanev 1985 • Berezinsky et al. 1986 large angles – non eclipsing binaries ISCRA Erice 2004

  3. Binary system What we need? no accretion small separation • star with massive & fast wind • WR or OB – perfect Binary with an energetic pulsar ISCRA Erice 2004

  4. The shock geometry • The geometry of the shock is described by the parameter  = Lem/(c MlossVWR), which is the ratio of momentum carried by the pulsar wind and the momentum of the stellar wind. Lem= 61031B122P-4 erg s-1, • The distance from the pulsar to the termination shock is:  = 1/2D(1+1/2) Ball & Dodd 2001 ISCRA Erice 2004

  5. Scenario ISCRA Erice 2004

  6. =0.06 Parameters Cygnus X-3 d=10kpc ISCRA Erice 2004

  7. Iron from the NS surface • Binding energy of the iron nuclei on the NS surface is not known (2-3keV?). • It is assumed that iron nuclei can be emitted for (Usov&Melrose, 1995) • Temp. of NS star surface can be high enough: • In a short time after its formation • As a result of heating of the polar cap by e-m cascades (polar cap model) ISCRA Erice 2004

  8. Acceleration of nuclei • Charged particles can be accelerated to the energy • Expected Lorentz factors of iron nuclei in Cyg X-3 then - 107 Arons 0.3 (for Crab) Arons, 1998 ISCRA Erice 2004

  9. Optical depth Optical depths for dissociation of single nucleon in the PWZ for different angles of injection (from 0 to 150) ISCRA Erice 2004

  10. Nucleons extraction Number of dissolved nucleons from primary iron nuclei during their propagation in the PWZ for angles from 0 to 150 ISCRA Erice 2004

  11. Shock zone • The magnetic field at the termination shock at the „pulsar side” is 103 G • Larmor radius for iron nuclei with Lorentz factor 106 is 1010 cm • Iron nuclei & protons can pass through the shock. ISCRA Erice 2004

  12. Magnetic field of WR star Eichler & Usov, 1993 rA- Alfven radius ISCRA Erice 2004

  13. Nucleons above the PWZ • Part of nucleons extracted from iron nuclei and remnant nuclei impinge onto the massive star. • Hadrons lose energy on pion production during their propagation in the WR star atmosphere Atmosphere model: Hamann 1985 ISCRA Erice 2004

  14. Can we get a neutrino? If pion decays and neutrino & muon are produced. ISCRA Erice 2004

  15. Spectra of neutrinos - comparison 0.2 Rstar- red 0.4 Rstar -green 0.6 Rstar - blue 0.8 Rstar - violet Lorentz factors -106 thick -107 thin Modulation due to companion star matter ISCRA Erice 2004

  16. Integral neutrino fluxes Integral neutrino fluxes as a function of the impact parameter for the observer in the plane of the binary system at energies above: 102GeV - black 3102GeV - red 103GeV - green 3103GeV – blue (=106 – thick, =107 – thin) ISCRA Erice 2004

  17. 180-210 =120-150 150-180 Spectra of neutrinos 210-240 240-270 270-300 Spectra of neutrinos for different viewing angles in respect to the plane of the binary; cos: 0.0-0.2 (black line), 0.2-0.4(red), 0.4-0.6(green) and 0.6-0.8(blue).  is azimuthal angle. ISCRA Erice 2004

  18. Conclusions • Heavy nuclei, if injected by a compact object inside the close massive binary (e.g. similar to Cyg X-3), can significantly disintegrate in the radiation field of a massive star. • Some neutrons dissolved from the nuclei impinge on the massive star surface producing high energy neutrinos in the plane of the massive binary. • Some protons and neutrons dissolved from nuclei and remnant nuclei, after propagation in the magnetic field of the massive star above the pulsar termination shock, can also impinge on the massive star surface producing neutrinos at large angles to the plane of the binary system. • The flux of neutrinos produced at large angles to the system plane is about 30% of the flux produced in the cone intercepted by the massive star in the considered case. ISCRA Erice 2004

  19. ISCRA Erice 2004

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