Presentation is loading. Please wait.

Presentation is loading. Please wait.

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

Similar presentations


Presentation on theme: "Super-Eddington Accretion: Models and Applications Jian-Min Wang Institute of High Energy Physics 2005, 4, 26."— Presentation transcript:

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 Radiation cross section Gravitation cross section

6 Radiative Equilibrium Equilibrium Condition:

7 Vertical Hydrodynamics: thin disk

8

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

10 Polish Doughnut

11 PP instability of Polish Doughnut Roche lobe: runaway instability removes PPI or Advection PPI

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

13 Boundary Condition Inner boundary: free-viscosity stress Outer boundary: standard disk solution

14 Solutions (1) Angular momentum distribution

15 S-shaped curve Solutions (2) Transition region?

16 Solutions (3) Flux from disk

17 Spectrum from slim disk Wang, Szuszkiewicz et al. (1999, ApJ, 522, 839) Characteristics: 1.A universe spectrum F  -1 2.Saturate luminosity L  Const.

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

19 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

20 Chen & Wang (2004)

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

22 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.

23 m BH =10 Accretion rate=10 3 t=10s Velocity And density profile

24 Accretion rate at Different radius (due to outflow)

25 Radiation luminosity from SEA, And compare with slim

26 cos i =1/8, 3/8, 5/8, 7/8

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

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

29 Emergent spectrum

30 Micro-quasars and NLS1s

31 NLS1 definitions 1)H  <2000km/s 2)Fe II or [Fe VII] 6087 [Fe X] 6375 3)[OIII]/ H  < 3 * radio-quiet, but loud

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

33 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

34 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


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

Similar presentations


Ads by Google