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Super-Eddington Accretion: Models and Applications

Super-Eddington Accretion: Models and Applications. Jian-Min Wang Institute of High Energy Physics 2005, 4, 26. Implications of SEA. Theoretical: one branch of accretion modes stable Applications: micro-quasars narrow line Seyfert 1 galaxies

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Super-Eddington Accretion: Models and Applications

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  1. Super-Eddington Accretion: Models and Applications Jian-Min Wang Institute of High Energy Physics 2005, 4, 26

  2. Implications of SEA • Theoretical: one branch of accretion modes stable • Applications: micro-quasars narrow line Seyfert 1 galaxies gamma-ray burst

  3. Outline • Polish Doughnut (Abramowicz astro-ph/0411185) 1. Super-Eddington radiation? 2. Wind? 3. Photon trapping? • Slim disk: 1) numerical results; 2) self-similar solution • Begelman’s model • Numerical simulation • Applications • Conclusions

  4. 1. Polish Doughnut:Possibility of Super-Eddington • Planck Limit

  5. Eddington Limit Gravitation cross section Radiation cross section

  6. Radiative Equilibrium Equilibrium Condition:

  7. Vertical Hydrodynamics: thin disk

  8. For a constant angular momentum, a0, we have Polish Doughnuts: Bernolli Equation

  9. Polish Doughnut

  10. PP instability of Polish Doughnut • Roche lobe: runaway instability removes PPI or Advection PPI

  11. Slim disk • Abramowicz et al. (1988) Radial motion  -angular momentum Vertical equilibrium Mass conservation Energy conservation Radiation transfer

  12. Boundary Condition • Inner boundary: free-viscosity stress • Outer boundary: standard disk solution

  13. Solutions (1) Angular momentum distribution

  14. Solutions (2) S-shaped curve Transition region?

  15. Solutions (3) Flux from disk

  16. Spectrum from slim disk Wang, Szuszkiewicz et al. (1999, ApJ, 522, 839) • Characteristics: • A universe spectrum • F  -1 • Saturate luminosity • L Const.

  17. Self-similar solution • Wang & Zhou (1999, ApJ, 614, 101) Photon trapping: saturate luminosity Bernoulli constant: Be < 0

  18. Comments on Slim Disk • Inner boundary condition • Radiation transfer: 1) radiation transfer 2) photon trapping: Qvis=Qrad+Qadv but tdiff<<tacc 3) decoupling the fluid and radiation

  19. Chen & Wang (2004)

  20. 2. Begelman’s model • Photon bubble instability (Gammie 1998) • Begelman (2002): “leaky” disk

  21. 3. Numerical simulations • 2-D simulations (Ohsuga et al. 2005) Viscous F. Radiation F. Basic Equations Boundary/Initial Conditions 3 R/ Rg 500 0    /2

  22. mBH=10 Accretion rate=103 t=10s Velocity And density profile

  23. Accretion rate at Different radius (due to outflow)

  24. Radiation luminosity from SEA, And compare with slim

  25. cos i =1/8, 3/8, 5/8, 7/8

  26. Future simulations • Including inhomogeneities due to photon bubble instability • FLD (flux limited diffusion) • SED (Comptonization etc.) • Viscosity

  27. Slim with corona: applications Wang & Netzer (2004); Chen & Wang (2004)

  28. Emergent spectrum

  29. Micro-quasars and NLS1s

  30. NLS1 definitions • H<2000km/s • Fe II or [Fe VII] 6087 • [Fe X] 6375 • [OIII]/ H < 3 • * radio-quiet, but loud

  31. Eddington ratio distribution How do SMBH grow in super-Eddington accretion?

  32. Growth of BH (Kawaguchi et al. (2004) Fraction of NLS1/NLQ: Marziani et al. (2003): ~11% in 215 low redshift (<0.8) Williams et al. (2002): ~15% in SDSS DR2 Grupe et al. (1999; 2004) Salvato et al. (2004): 31-46% in soft X-ray selected AGNs T~1-3*107years BLQs: 0.1-5Gyr

  33. Summary • Theoretical models 1) slim disk? 2) leaky disk driven by photon bubble 3) corona 4) outflow/jet? • Emergent spectrum 1) occulation; 2) GR effects; 3) radiation transfer • Slim with hot corona, jet? • Applications

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