Structure Evolution of Protoplanetary Disks Merging 3 D

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

Data Radiation Transfer Models & Observational Signatures Theory 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: 3 D Monte Carlo techniques

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 • • • 3 D 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 0 Class II

Star Formation: Observations l. Fl “ 0” 1 10 “I” 1000 BHR 71 1 10 1000 “II” l(mm) IRAS 04302+2247 Padgett et al. 1999 Bourke 2001 1 10 1000 TW Hydrae Krist et al. 2000

Near-IR HST Images

Disks, Disks…

T Tauri Accretion Disks: Images Disk density: hydrostatic flared disk: h / r = cs(r) / W(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 400 AU • • i = 25 i = 75 i = 85 Whitney & Hartmann 1992

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

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

L 1551 Region L 1551 IRS 5 HL Tau XZ Tau HH 30 IRS Red = [S II] White = Visual 1’ = 8400 AU Whitney, Gomez, & Kenyon (Mt Hopkins, 48”)

HH 30 IRS Accretion Disk HST WFPC 2: Green: F 555 W (V Band) Red: F 617 N (Ha, S[II]) Bacciotti et al. 1999 Scattered light models: Assume ISM dust opacity Image morphology: disk geometry, inclination Width of dust lane: optical depth, disk mass Burrows et al. 1996

HH 30 IRS: Disk Geometry HST WFPC 2 Model Hydrostatic flared disk, i = 84 Dust + gas suspended above midplane Consistent with T(r), S(r) for irradiated disks (D’Alessio et al. 1999)

Multiwavelength Models V (0. 55 mm) ISM Dust: I (0. 85 mm) K (2. 25 mm) Opacity decreases by 10 from V to K Dust lane width decreases into IR Very compact nebulosity at K Wood et al. 1998

V (0. 55 mm) I (0. 85 mm) K (2. 25 mm) NICMOS: Wide dust lane at K Circumstellar dust is GRAYER than ISM dust Grain Growth in disk Cotera et al. 2001

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 (t ~ k. M) Md ~ 2 * 10 -3 M 8 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 mm Grayer opacity, Sub-mm slope ~ 1/l Beckwith & Sargent (1991): sub-mm continuum SEDs: k ~ 1/l

HH 30 IRS: Image Variability

Magnetic Accretion in HH 30 IRS • • Stellar 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 & Lamb 1979 Shu et al. 1994

Magnetic Accretion in HH 30 IRS Wood & Whitney 1998

Magnetic Accretion in HH 30 IRS • T*=3500 K; Ts=10000 K; DA ~ 6% • Asymmetric brightening; DV ~ 1. 5 m • Photometric centroid shift: d ~ 0. 5’’ Wood & Whitney 1998 Stapelfeldt et al. 1999

HH 30 IRS: Photometry Wood et al. 2000 DV ~ 1. 5 mag, DT ~ days: Typical of CTTs, accretion hot spots Variability all due to scattered light

GM Aur: Disk/Planet Interaction? 1200 AU Schneider et al. 2002 • NICMOS coronagraph • Scattered light modeling: • Mdisk ~ 0. 04 M 8; Rdisk ~ 300 AU; i ~ 50

GM Aur: Disk/Planet Interaction? • No near-IR excess • SED model requires 4 AU gap: planet? • Lin & Papaloizou; Seyer & Clarke; Nelson, etc

GM Aur: Disk/Planet Interaction? Rice et al. 2002 • 3 D SPH calculation from Ken Rice • Planet at 2. 5 AU clears disk out to 4 AU

GM Aur: Disk/Planet Interaction? Rice et al. 2002 • 3 D SPH calculation from Ken Rice • Planet at 2. 5 AU clears disk out to 4 AU

GM Aur: Disk/Planet Interaction? Rice et al. 2002 • 3 D SPH density grid into Monte Carlo code • SIRTF SED can discriminate planet mass • Centroid shifting ~ 0. 1 mas: Keck, SIM?

Disk Evolution Trapezium Cluster IR-EXCESS = DISKS Cluster age ~ 1. 5 Myr Disk Frequency: 80% Lada et al. 2000

Disk Lifetimes CLUSTER SURVEYS: Disk frequency declines with cluster age Disk Lifetime: ~ 6 Myr Haisch et al. 2000

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

SED Evolution Wood et al. 2002 d = 500 pc; 10 -8 M 8 < Md < 10 -1 M 8 SIRTF 5 s, 500 secs

Color Evolution Wood et al. 2001

Observing Disk Evolution • • JHKL surveys: disk frequency & lifetime JHKL surveys: detect Md > 10 -7 M 8 Far-IR & (sub)mm: disk mass evolution Mid-IR (10 mm & 25 mm): disk mass evolution

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

Disk Masses in Taurus-Auriga 1 = 10 -1 M 8 2 = 10 -2 M 8 3 = 10 -3 M 8 etc Evolution models: disk clearing rapid for Md < 10 -6 M 8 Wood et al. 2002

Space Infrared Telescope • • • SIRTF: launch in January 2003 Lot’s of data: 6 Legacy programs Infrared spectra for 3 mm < l < 160 mm 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 T 6 AU 20 AU 300 AU r 1/5 • Stellar photons absorbed at ~ 4 h(r) above midplane • Iterate with dynamics • Self-consistent disk structure

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* = 40000 K Q(H 0) = 4. 26 1049 s-1 n(H) = 100 cm-3 Calculate 3 D ionization structure Study percolation of ionizing photons in fractal ISM

Stromgren Volume in a Dickey-Lockman Disk 2 Kpc f ~ 10 -3 n(H 0) Ionization fraction Q(H 0) = 2 1050 s-1: Escape fraction = 22% Ionization of HVCs, Magellanic Stream, IGM…

3 D Stromgren Volumes n(H 0) (before) Ionization fraction n(H 0) (after) Clumpy density; 2 sources with Q(H 0) = 2 1050 s-1 3 D ionization structure, shadow regions