Monte Carlo Radiation Transfer in Protoplanetary Disks: Disk-Planet Interactions Kenneth Wood St Andrews

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:Rachel Akeson, Charlie Lada, Ed Churchwell, Glenn Schneider, Angela Cotera, Keivan Stassun

Monte Carlo Development History Scattered light disks & envelopes (1992) 3D geometry & illumination (1996) Dust radiative equilibrium (2001) SEDs disks + envelopes Monte Carlo for disk surface + diffusion for interior (2002) Density grids from SPH simulations (2003) Spatial variation of dust opacity (2003) Self consistent vertical hydrostatic equilibrium (2004) 1992: Predictions1996: HST data GM Aur: 4AU gap, disk-planet interaction

Disk Structure Calculations Our models used parameterized disks: power laws for  (r), h(r) Disk theory: reduce model parameter space Irradiated accretion disks:  ~ r -1, h ~ r 1.25 (D’Alessio, Calvet, & collaborators) New Monte Carlo: iterate for disk structure (Walker et al. 2004) Model disk-planet interactions in GM Aur

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

Protoplanetary Disks Need high resolution imaging: ALMA Gap clearing simulation images: 700  m700  m ALMA simulation Wolf et al. 2002

Inner Gaps from SED Modeling Remove inner disk material: redistribute near-IR excess emission to longer s R in = 7R * R in = 4 AU GM Aur See also:Dullemond, et al. Calvet, D’Alessio Rice et al. (2003)

Estimating R in from SEDs Hot inner edge emits in IR Include inner edge emission when estimating R in 6 AU20 AU300 AU T  1/5 GM Aur

Monte Carlo, R in = 4 AU, i = CG97, R in = 0.1 AU CG97, R in = 4 AU Vertical Hydrostatic Equilibrium GM Aur

Disk Dust: Grain Growth ISM Disk dust Dust Size Distribution: Power law + exponential decay Grain sizes in excess of 50  m Grayer opacity compared to ISM  Fits HH30, GM Aur, AA Tau, … Opacity slopes: Dust model:  sub-mm ~   B /  K ~ 2.5 Beckwith & Sargent (1991): sub-mm continuum SEDs:  ~  Watson & Stapelfeldt (2004): HH 30 IRS:  B /  K ~ 1.5 – 4.5

GM Aur: Disk/Planet Interaction? NICMOS coronagraph Scattered light modeling: M disk ~ 0.04 M  ; R disk ~ 300 AU; i ~ 50 Schneider et al AU

GM Aur: Disk/Planet Interaction? Tiny near-IR excess: inner hole first suggested by Koerner, Sargent, & Beckwith (1993) SED model requires 4AU gap: planet?

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

GM Aur: Disk/Planet Interaction? Higher mass “planets”: sharper truncation Rice et al. 2003

GM Aur: Disk/Planet Interaction? Spitzer SED can discriminate “planet” mass Centroid shifting ~ 0.1mas: Keck, SIM? Rice et al M p = 2M J M p = 50M J

More Disks with Gaps IRTF: Bergin, Calvet, Sitko, et al. (2004) Gap sizes: 3 AU < R gap < 7 AU Silicate emission: smaller grains in inner disk Sharp truncation, very low density inner disks GM AurTW HyaLk Ca 15DM Tau

GM Aur: 6.5 AU Gap SED model requires low density material in cleared region Inner disk mass ~ M  High resolution imaging of inner holes…?

GM Aur: 6.5 AU Gap Inner disk mass ~ M  T  1/5

Low density material in gap “fills in” images Inner gaps more obvious in SEDs !!  m  m  m

Summary & Future Research Monte Carlo: self-consistent disk structure calculations GM Aur:Disk-planet interaction, need mid-IR data Direct imaging of inner gaps: low density material “fills in” surface brightness => SEDs find gaps! Coding:Radiation pressure Include gas opacity Transiently heated grains Goal: merge radiation transfer & hydro Codes now available at: