Download presentation
Presentation is loading. Please wait.
Published byArchibald Allison Modified over 9 years ago
1
A Submillimeter View of Protoplanetary Disks Sean Andrews University of Hawaii Institute for Astronomy Jonathan Williams & Rita Mann, UH IfA David Wilner, Harvard-Smithsonian CfA and
2
outline 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
3
constraints on the planet formation process ? initial conditionsfinal products empirical constraints from sub-mm observations viscous accretion photoevaporation particle growth
4
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
5
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
6
Andrews & Williams (2005) >5x more sensitive M d > 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 Disks
7
evolution of outer disk properties sub-mm emission (disk masses) decreases with IR SED evolution sub-mm SED changes with IR SED evolution (particle growth) Class I disks Class II disks Class III disks Andrews & Williams (2005)
8
e.g., Haisch et al. (2001) outer 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) 5-10 Myr scarce: few % inner & outer disk signatures disappear on similar timescales [also Skrutskie et al. (1990), Mamajek et al. (2004), etc.] Andrews & Williams (2005)
9
SMA Imaging Survey of Protoplanetary Disks 24 disks with ~ 1 - 2” resolution at 880 m / 1.3 mm continuum + 12 CO J=3 - 2 / J=2 - 1 Andrews & Williams (2007) 10” 1500 AU 12 disks in Tau-Aur and 12 in Oph-Sco 04158+2805 AA Tau CI Tau DH Tau DL Tau DM Tau DN Tau DR Tau FT Tau GM Aur GO Tau RY Tau AS 205 AS 209 DoAr 25 DoAr 44 Elias 24 GSS 39 L1709 B SR 21 SR 24 WaOph 6 WSB 60 WL 20
10
measuring circumstellar disk structure SED geometrically thin irradiated disk visibilities T R-qT R-q MdMd R-p R-p RdRd simultaneously fit SED & SMA visibilities
11
measuring circumstellar disk structure SED geometrically thin irradiated disk visibilities T R-qT R-q MdMd R-p R-p RdRd simultaneously fit SED & SMA visibilities 2 11 33 55 derive temperature & density distributions, disk sizes datamodelresidual and repeat for 20+ disks…
12
temperatures: densities: sizes and masses: T R - q median q 0.6 1 AU temperature 200 K R - p median p 0.7-1.0* 1 AU surface density 150 g/cm 2 median R d 200 AU median M d 0.05 solar masses disk structure results Andrews & Williams (2007) [see also, e.g., Lay et al. (1997), Kitamura et al. (2002), etc.]
13
comparison with viscous accretion disk properties to conserve angular momentum, disk spreads thin as it accretes = c s H change in and R d with age sets timescale = 0.001 = 0.01 = 0.1 Hartmann et al. (1998) fiducial model behavior
14
comparison with viscous accretion disk properties = c s H change in and R d with age sets timescale = 0.001 = 0.01 = 0.1 Hartmann et al. (1998) fiducial model behavior = 0.01
15
a different environment: Taurus to Orion mass loss rate of 10 -7 M /yr evaporation timescale of 10 5 yr Churchwell et al. (1987) quiescent, low-mass crowded, high-mass C. R. O’Dell photoevaporating proplyds
16
a different environment: Taurus to Orion mass loss rate of 10 -7 M /yr evaporation timescale of 10 5 yr Churchwell et al. (1987) quiescent, low-mass crowded, high-mass C. R. O’Dell photoevaporating proplyds does enough disk mass remain to form planetary systems?
17
Mundy et al. (1995) BIMA Bally et al. (1998) OVRO Lada (1999) PdBI detecting thermal disk emission in the Trapezium 1 mm = 1 cm Williams, Andrews, & Wilner (2005)
18
Mundy et al. (1995) BIMA Bally et al. (1998) OVRO Lada (1999) PdBI detecting thermal disk emission in the Trapezium 1 mm = 1 cm Williams, Andrews, & Wilner (2005) high spatial resolution: filter out cloud emission separate disks in crowded region high frequency: more sensitive to thermal emission less contamination
19
0.019 M 0.016 M 0.024 M 0.013 M 4/23 disks with M d M MMSN masses of the Orion proplyds Williams, Andrews, & Wilner (2005) see also Eisner & Carpenter (2006)
20
Rita Mann - UH IfA dissertation 0.019 M 0.014 M masses of the Orion proplyds detections are similar to Tau-Aur Class II detection statistics (10-20%)?
21
summary 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)
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.