a submillimeter view of protoplanetary disks
DESCRIPTION
A Submillimeter View of Protoplanetary Disks. Sean Andrews. University of Hawaii Institute for Astronomy. and. Jonathan Williams & Rita Mann, UH IfA. David Wilner, Harvard-Smithsonian CfA. SMA constraints on disk structure :. - density, temperature, opacity, size measurements - PowerPoint PPT PresentationTRANSCRIPT
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)