A Submillimeter View A Submillimeter View of Protoplanetary of Protoplanetary

DisksDisksSean AndrewsSean Andrews

University of Hawaii Institute for AstronomyUniversity of Hawaii Institute for Astronomy

Jonathan Williams & Rita Mann, UH IfAJonathan Williams & Rita Mann, UH IfADavid Wilner, Harvard-Smithsonian CfADavid Wilner, Harvard-Smithsonian CfA

andand

outlineoutline

• sub-mm photometry of Tau-Aur disks:

- outer disk fraction and radial evolution timescale- disk mass and sub-mm color evolution

• SMA constraints on disk structure:

- density, temperature, opacity, size measurements- compare with evolution of a viscous accretion disk

• SMA detections of Orion proplyds:

- compare with a more harsh environment- disk masses and planet formation prospects

constraints on the planet formation process

?

initial conditions final products

empirical constraints from sub-mm observations

viscous accretionphotoevaporation

particle growth

SED: thermal emission from irradiated thin dust

disk

different disk regions

contribute at different based on local

temperature and density conditions

Q: why sub-mm observations? A: to trace most of the disk

1-2”~0.3”

~0.5 km ~100 m

spatial emission distribution:

low sub-mm optical depths; continuum

emission sensitive to distribution of density near the disk midplane

angular resolution

baseline lengths

Q: why sub-mm observations? A: to resolve the disk structure

Andrews & Williams (2005)

>5x more sensitive

Md > 1 Jupiter mass

uniform flux limits

scaled 1.3 mm surveys: Beckwith et al. (1990), Osterloh & Beckwith (1995); Andre & Montmerle (1994)

SCUBA

SHARC-II

• 153 Taurus disks + 47 Ophiuchus disks (SpT < M5, 1-3 Myr)• 350, 450, and 850 m; deep and uniform (3 to <10 mJy)

Multiwavelength Single-Dish Survey of DisksMultiwavelength Single-Dish Survey of Disks

evolution of outer disk propertiesevolution of outer disk properties

sub-mm emission(disk masses)

decreases with IR SED evolution

sub-mm SEDchanges with

IR SED evolution(particle growth)

Class I disks

Class II disks

Class III disks

Andrews & Williams (2005)

e.g., Haisch et al. (2001)

outer disk fraction/radial evolution timescalesouter disk fraction/radial evolution timescales

transition disks: • sub-mm emission (outer disk) • no excess IR emission (inner disk)

what about the outer disk?(sub-mm detection fraction)

55--10 Myr10 Myr

scarce: few %

inner & outer disk signaturesdisappear on similar timescales

[also Skrutskie et al. (1990), Mamajek et al. (2004), etc.]

Andrews & Williams (2005)

SMA Imaging Survey of Protoplanetary DisksSMA Imaging Survey of Protoplanetary Disks

• 24 disks with ~1-2” resolution at 880 m / 1.3 mm

• continuum + 12CO J=3-2 / J=2-1Andrews & Williams (2007)

10”

1500 AU

12 disks in Tau-Aur and 12 in Oph-Sco04158+2805AA TauCI TauDH Tau

DL TauDM TauDN TauDR Tau

FT TauGM AurGO TauRY Tau

AS 205AS 209DoAr 25DoAr 44

Elias 24GSS 39L1709 BSR 21

SR 24WaOph 6WSB 60WL 20

measuring circumstellar disk structuremeasuring circumstellar disk structure

SED

geometrically thin irradiated disk

visibilities

T R-q Md R-p Rd

simultaneously fit SED & SMA visibilities

measuring circumstellar disk structuremeasuring circumstellar disk structure

SED

geometrically thin irradiated disk

visibilities

T R-q Md R-p Rd

simultaneously fit SED & SMA visibilities

2

1 3 5

derive temperature & density distributions, disk sizes

data model residual

and repeat for 20+ disks…

temperatures:

densities:

sizes and masses:

T R-q median q 0.61 AU temperature 200 K

R-p median p 0.7-1.0*1 AU surface density 150 g/cm2

median Rd 200 AUmedian Md 0.05 solar masses

disk structure resultsdisk structure results

Andrews & Williams (2007) [see also, e.g., Lay et al. (1997), Kitamura et al. (2002), etc.]

comparison with viscous accretion disk propertiescomparison with viscous accretion disk properties

to conserve angular momentum,disk spreads thin as it accretes = cs H

change in and Rd with age

sets timescale

= 0.001 = 0.01 = 0.1Hartmann et al. (1998)fiducial model behavior

comparison with viscous accretion disk propertiescomparison with viscous accretion disk properties

= cs H

change in and Rd with age

sets timescale

= 0.001 = 0.01 = 0.1Hartmann et al. (1998)fiducial model behavior

= 0.01

a different environment: Taurus to Oriona different environment: Taurus to Orion

mass loss rate of 10-7 M/yrevaporation timescale of 105 yr

Churchwell et al. (1987)

quiescent, low-mass

crowded, high-mass

C. R. O’Dell

photoevaporating proplyds

a different environment: Taurus to Oriona different environment: Taurus to Orion

mass loss rate of 10-7 M/yrevaporation timescale of 105 yr

Churchwell et al. (1987)

quiescent, low-mass

crowded, high-mass

C. R. O’Dell

photoevaporating proplyds

does enough disk mass remain toform planetary systems?

Mundy et al. (1995)

BIMA

Bally et al. (1998)

OVRO

Lada (1999)

PdBI

detecting thermal disk emission in the Trapeziumdetecting thermal disk emission in the Trapezium

1 mm = 1 cmWilliams, Andrews, & Wilner (2005)

Mundy et al. (1995)

BIMA

Bally et al. (1998)

OVRO

Lada (1999)

PdBI

detecting thermal disk emission in the Trapeziumdetecting thermal disk emission in the Trapezium

1 mm = 1 cmWilliams, Andrews, & Wilner (2005)

high spatial resolution: • filter out cloud emission• separate disks in crowded region

high frequency: • more sensitive to thermal emission• less contamination

0.019 M

0.016 M

0.024 M

0.013 M

4/23 disks with Md MMMSN

masses of the Orion proplydsmasses of the Orion proplyds

Williams, Andrews, & Wilner (2005)

see also Eisner & Carpenter (2006)

Rita Mann - UH IfA dissertation

0.019 M

0.014 M

masses of the Orion proplydsmasses of the Orion proplyds

detections are similar to Tau-Aur Class II

detection statistics (10-20%)?

summarysummary

Andrews & Williams (2005)

• sub-mm photometry of Tau-Aur disks:

- radial evolution appears to be rapid (photoevap.?)- sub-mm properties evolve on similar sequence as IR

• SMA constraints on disk structure:

- large, homogeneous sample of physical conditions- broadly consistent with accretion disk for = 0.01

Andrews & Williams (2007)

• SMA detections of Orion proplyds:

- Trapezium still contains some MMSN disks- detections similar to Tau-Aur disks; bimodal dist.?

Williams et al. (2005) Rita Mann’s thesis (UH - IfA)