1. Kenneth Wood St Andrews
Monte Carlo Radiation Transfer in Protoplanetary Disks: Disk-Planet Interactions, Structure and Warping
Kenneth Wood
St Andrews

2. Radiation Transfer + Hydrodynamics
RT Models: Barbara Whitney, Jon Bjorkman,
Christina Walker, Mark O’Sullivan
Dust Theory: Mike Wolff
SPH Models: Ken Rice, Mike Truss, Ian Bonnell
Observations: Charlie Lada, Ed Churchwell,
Glenn Schneider, Angela Cotera,
Keivan Stassun

3. Monte Carlo Development History
Scattered light disks & envelopes (1992)
3D geometry & illumination (1996)
Dust radiative equilibrium (2001)
Monte Carlo for disk surface diffusion for interior (2002)
Density grids from SPH simulations (2002)
Spatial variation of dust opacity (2003)
Self consistent vertical hydrostatic equilibrium (2003)
1992: Predictions
1996: HST data
GM Aur: 4AU gap,
disk-planet interaction

4. Disk Structure Calculations
Above used parameterized disks: power laws for S(r), h(r)
Disk theory: reduce model parameter space
Irradiated accretion disks: S ~ r -1, h ~ r (D’Alessio, Calvet, & collaborators)
New Monte Carlo: iterate for disk structure (Walker et al. 2004)
Model disks around GM Aur and AA Tau

5. Disk-Planet Interactions: Gap Clearing
Simulation from
Ken Rice & Phil Armitage
Papaloizou, Lin, Bodenheimer, Lubow,
Artymowicz, Nelson, D’Angelo, Kley, …
Observational signatures: images, SEDs?

6. Protoplanetary Disks Need high resolution imaging: ALMA
Gap clearing simulation images:
700mm
700mm ALMA simulation
Wolf et al. 2002

7. Inner Gaps from SED Modeling
Remove inner disk material: remove near-IR excess emission
Rin = 7R*
Rin = 4 AU
GM Aur

8. GM Aur: Disk/Planet Interaction?
Schneider et al. 2003
NICMOS coronagraph
Scattered light modeling:
Mdisk ~ 0.04 M8; Rdisk ~ 300 AU; i ~ 50

9. GM Aur: Disk/Planet Interaction?
No near-IR excess
SED model requires 4AU gap: planet?

10. GM Aur: Disk/Planet Interaction?
Rice et al. 2003
3D SPH calculation from Ken Rice
Planet at 2.5AU clears inner 4AU in ~2000 yr

11. GM Aur: Disk/Planet Interaction?
Rice et al. 2003
3D SPH calculation from Ken Rice
Planet at 2.5AU clears inner 4AU in ~2000 yr

12. GM Aur: Disk/Planet Interaction?
Mp = 2MJ
Mp = 50MJ
Rice et al. 2003
Spitzer SED can discriminate planet mass
Centroid shifting ~ 0.1mas: Keck, SIM?

13. GM Aur: Disk/Planet Interaction?
TW Hya
Rice et al. 2003
Calvet et al. 2002
Spitzer SED can discriminate planet mass
Centroid shifting ~ 0.1mas: Keck, SIM?

14. AA Tau: Large and Small Scale Disk Structure
Photopolarimetry (Bouvier, Menard, et al.) P ~ 8.4 days, DV ~ 1 mag, D(B-V) ~ 0 Star eclipsed by warp in inner disk
SED model to get disk structure
Warped disk model for photopolarimetry
SPH: tilted dipole warps disk

15. AA Tau SED Modeling T = 4000 K, R = 2R8, M = 0.5M8
M = 2e-9 M8/yr, Rd = 200 AU, i = 70
O’Sullivan et al. (2004)

16. Analytic Disk Warp AA Tau: P ~ 8.4 days
Warp at r ~ 0.07 AU, amplitude ~ 0.02 AU
O’Sullivan et al. (2004)

17. Photopolarimetry SimulationDV
DV ~ 1 mag
DP ~ 0.3%
P (%) PA
O’Sullivan et al. (2004)

18. SPH Simulation
Inclined dipole field: include magnetic force in SPH code (NOT MHD!)
Need B = 2 kG, at latitude q = 65 (see also Terquem & Papaloizou)

19. Summary & Future Research
Monte Carlo: self-consistent disk structure calculations
GM Aur: Disk-planet interaction, need Spitzer SEDs
AA Tau: SED model for disk structure Warped disk for photopolarimetry SPH: dipole B = 2 kG, at latitude q = 65
Coding: Radiation pressure Include gas opacity Transiently heated grains
Goal: merge radiation transfer & hydro
Codes now available at:

20. Disk Dust: Grain Growth
ISM
Disk dust
Dust Size Distribution:
Power law + exponential decay
Grain Sizes in excess of 50mm
Grayer opacity, Sub-mm slope ~ 1/l
Fits HH30, GM Aur, AA Tau
Beckwith & Sargent (1991): sub-mm continuum SEDs: k ~ 1/l

21. Estimating Rin from SEDs
6 AU
20 AU
300 AU T
r1/5
GM Aur
Hot inner edge emits in IR
Include inner edge emission when estimating Rin

22. Vertical Hydrostatic Equilibrium
GM Aur
Monte Carlo, Rin = 4 AU, i =
CG97, Rin = 0.1 AU
CG97, Rin = 4 AU

23. Estimating Rin from SEDs
Monte Carlo
CG97
KH87
ALS87
MC models include inner edge emission
Other models without inner edge emission
No 10mm excess MC: Rin > 10 AU CG: Rin ~ 2.5 AU

24. Disk Structure
Walker et al. (2004)

25. SEDs
D’Alessio: i = 60
MC: i = 63
MC: i= 60
Walker et al. (2004)

26. Comparison Summary
MC: Disk slightly hotter at large radii Slightly more emission in mm
Differences: Radiation pressure Dust opacity Treatment of upper layers Non-isotropic scattering Radial transport in outer disk