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Super-Eddington Accretion: Models and Applications Jian-Min Wang Institute of High Energy Physics 2005, 4, 26
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Implications of SEA Theoretical: one branch of accretion modes stable Applications: micro-quasars narrow line Seyfert 1 galaxies gamma-ray burst
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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
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1. Polish Doughnut: Possibility of Super-Eddington Planck Limit
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Eddington Limit Radiation cross section Gravitation cross section
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Radiative Equilibrium Equilibrium Condition:
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Vertical Hydrodynamics: thin disk
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For a constant angular momentum, a 0, we have Polish Doughnuts: Bernolli Equation
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Polish Doughnut
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PP instability of Polish Doughnut Roche lobe: runaway instability removes PPI or Advection PPI
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Slim disk Abramowicz et al. (1988) Radial motion -angular momentum Energy conservation Radiation transfer Vertical equilibrium Mass conservation
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Boundary Condition Inner boundary: free-viscosity stress Outer boundary: standard disk solution
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Solutions (1) Angular momentum distribution
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S-shaped curve Solutions (2) Transition region?
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Solutions (3) Flux from disk
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Spectrum from slim disk Wang, Szuszkiewicz et al. (1999, ApJ, 522, 839) Characteristics: 1.A universe spectrum F -1 2.Saturate luminosity L Const.
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Self-similar solution Wang & Zhou (1999, ApJ, 614, 101) Photon trapping: saturate luminosity Bernoulli constant: Be < 0
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Comments on Slim Disk Inner boundary condition Radiation transfer: 1) radiation transfer 2) photon trapping: Q vis =Q rad +Q adv but t diff <<t acc 3) decoupling the fluid and radiation
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Chen & Wang (2004)
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2. Begelman’s model Photon bubble instability (Gammie 1998) Begelman (2002): “leaky” disk
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3. Numerical simulations 2-D simulations (Ohsuga et al. 2005) Basic Equations Boundary/Initial Conditions 3 R/ R g 500 0 /2 Radiation F. Viscous F.
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m BH =10 Accretion rate=10 3 t=10s Velocity And density profile
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Accretion rate at Different radius (due to outflow)
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Radiation luminosity from SEA, And compare with slim
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cos i =1/8, 3/8, 5/8, 7/8
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Future simulations Including inhomogeneities due to photon bubble instability FLD (flux limited diffusion) SED (Comptonization etc.) Viscosity
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Slim with corona: applications Wang & Netzer (2004); Chen & Wang (2004)
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Emergent spectrum
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Micro-quasars and NLS1s
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NLS1 definitions 1)H <2000km/s 2)Fe II or [Fe VII] 6087 [Fe X] 6375 3)[OIII]/ H < 3 * radio-quiet, but loud
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Eddington ratio distribution How do SMBH grow in super-Eddington accretion?
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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*10 7 years BLQs: 0.1-5Gyr
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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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