Structure & Evolution of Protoplanetary Disks: Merging 3D Radiation Transfer & Hydrodynamics Kenneth Wood St Andrews

Data:Imaging polarimetry Photometric monitoring Scattered light images Spectral energy distributions (SEDs) Theory:Dynamical models of star formation: Collapsing clouds, jets, accretion disks, debris disks, & planet formation RT Models:3D Monte Carlo techniques DataTheory Radiation Transfer Models & Observational Signatures

Friends & Collaborators RT Models & Dust Theory:Barbara Whitney, Jon Bjorkman, Mike Wolff Dynamical Models:Ken Rice, Ian Bonnell, Phil Armitage, Matthew Bate, Scott Kenyon, Adam Frank Observations:Charlie Lada, Ed Churchwell, Anneila Sargent, Glenn Schneider, Angela Cotera, Debbie Padgett, Keivan Stassun

Monte Carlo Capabilities 3D geometry & illumination Incorporate MHD density & velocity grids Scattered light images (optical & infrared) Radiative equilibrium dust temperatures SEDs & thermal imaging (mid-IR, sub-mm)

Star Formation Theory Class 0Class IClass II

Star Formation: Observations ( m) F Bourke 2001 Padgett et al Krist et al BHR71TW HydraeIRAS III

Near-IR HST Images

Disks, Disks, Disks…

T Tauri Accretion Disks: Images Disk density: hydrostatic flared disk: h / r = c s (r) / (r) Shakara & Sunyaev (1973), Lynden-Bell & Pringle (1974) Direct starlight 10,000 brighter than scattered light from disk Best detected when star occulted by edge-on flaring disk Whitney & Hartmann 1992 i = 25i = 75i = AU

T Tauri Accretion Disks: SEDs Pole-on:Large IR excess Edge-on: Double peaked SED:scattered light + thermal Wood et al. 2002

Star Formation in Taurus © Steve Kohle & Till Credner, AlltheSky.com

L1551 Region Whitney, Gomez, & Kenyon (Mt Hopkins, 48) Red = [S II] White = Visual L1551 IRS5 HL Tau XZ Tau HH 30 HH 30 IRS 1 = 8400AU

HH 30 IRS Accretion Disk Burrows et al HST WFPC2: Green:F555W (V Band) Red:F617N (H, S[II]) Scattered light models: Assume ISM dust opacity Image morphology: disk geometry, inclination Width of dust lane: optical depth, disk mass Bacciotti et al. 1999

HH 30 IRS: Disk Geometry HST WFPC2 Model Hydrostatic flared disk, i = 84 Dust + gas suspended above midplane Consistent with T(r), (r) for irradiated disks (DAlessio et al. 1999)

Multiwavelength Models ISM Dust:Opacity decreases by 10 from V to K Dust lane width decreases into IR Very compact nebulosity at K Wood et al V (0.55 m)I (0.85 m)K (2.25 m)

Cotera et al V (0.55 m) I (0.85 m) K (2.25 m) NICMOS: Wide dust lane at K Circumstellar dust is GRAYER than ISM dust Grain Growth in disk

HH 30 IRS: SED Models Model:Geometry from HST images; Heating: starlight + accretion Model HST images and SED: Determine dust size distribution Find:Grayer opacity Optical opacity < ISM Larger disk mass ( ~ M) M d ~ 2 * M Wood et al. 2002

HH 30 IRS: Grain Growth ISM HH 30 IRS Dust Size Distribution: Power law + exponential decay Grain Sizes in excess of 50 m Grayer opacity, Sub-mm slope ~ 1/ Beckwith & Sargent (1991): sub-mm continuum SEDs: ~ 1/

HH 30 IRS: Image Variability

Magnetic Accretion in HH 30 IRS BStellar B-field not aligned with rotation axis Truncates disk, accretion along field lines Hot Spots on star at magnetic poles UV excess, photometric modulation B Ghosh & Lamb1979 Shu et al. 1994

Magnetic Accretion in HH 30 IRS Wood & Whitney 1998

Magnetic Accretion in HH 30 IRS T * =3500K; T s =10000K; A ~ 6% Asymmetric brightening; V ~ 1.5m Photometric centroid shift: ~ 0.5 Wood & Whitney 1998 Stapelfeldt et al. 1999

HH 30 IRS: Photometry V ~ 1.5mag, T ~ days: Typical of CTTs, accretion hot spots Variability all due to scattered light Wood et al. 2000

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? No near-IR excess SED model requires 4AU gap: planet? Lin & Papaloizou; Seyer & Clarke; Nelson, etc

GM Aur: Disk/Planet Interaction? 3D SPH calculation from Ken Rice Planet at 2.5 AU clears disk out to 4AU Rice et al. 2002

GM Aur: Disk/Planet Interaction? 3D SPH calculation from Ken Rice Planet at 2.5 AU clears disk out to 4AU Rice et al. 2002

GM Aur: Disk/Planet Interaction? 3D SPH density grid into Monte Carlo code SIRTF SED can discriminate planet mass Centroid shifting ~ 0.1mas: Keck, SIM? Rice et al. 2002

Disk Evolution Lada et al Trapezium Cluster IR-EXCESS = DISKS Cluster age ~ 1.5Myr Disk Frequency: 80%

Disk Lifetimes Haisch et al CLUSTER SURVEYS: Disk frequency declines with cluster age Disk Lifetime: ~ 6Myr

Disk Evolution Disk structure does not change Disk mass decreases homologously Mass = mass of dust contributing to SED What M d can near-IR surveys detect? Observables: SEDs, colors Current evidence for disk mass evolution?

SED Evolution d = 500pc; M < M d < M SIRTF 5, 500secs Wood et al. 2002

Color Evolution Wood et al. 2001

Observing Disk Evolution JHKL surveys: disk frequency & lifetime JHKL surveys: detect M d > M Far-IR & (sub)mm: disk mass evolution Mid-IR (10 m & 25 m): disk mass evolution

Taurus-Auriga Sources Gap in K-N distribution: transition from disks to no disks Kenyon & Hartmann 1995 * = I + = II ( = III

Disk Masses in Taurus-Auriga Evolution models: disk clearing rapid for M d < M Wood et al = M 2 = M 3 = M etc

Space Infrared Telescope SIRTF: launch in January 2003 Lots of data: 6 Legacy programs Infrared spectra for 3 m < < 160 m Study disks: environments and ages Website with grid of models

Feedback in Star Formation HH 30 IRS, GM Aur: Signatures of magnetic accretion & SPH models Bigger Goal: Combine RT and hydro simulations Temperature, radiation pressure & ionization structure

Disk Temperature Structure Stellar photons absorbed at ~ 4 h(r) above midplane Iterate with dynamics Self-consistent disk structure 6 AU20 AU300 AU T 1/5

Summary & Future Research Disk Structure & Variability: HH 30, GM Aur Model data with analytic density structures Now testing hydro simulations SIRTF: characterize large numbers of disks Goal: merge radiation transfer & hydro

Monte Carlo Photoionization T * = K Q(H 0 ) = s -1 n(H) = 100 cm -3 Calculate 3D ionization structure Study percolation of ionizing photons in fractal ISM

Stromgren Volume in a Dickey-Lockman Disk 2 Kpc n(H 0 )Ionization fraction f ~ Q(H 0 ) = s -1 : Escape fraction = 22% Ionization of HVCs, Magellanic Stream, IGM…

3D Stromgren Volumes n(H 0 ) (before)Ionization fractionn(H 0 ) (after) Clumpy density; 2 sources with Q(H 0 ) = s -1 3D ionization structure, shadow regions