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The Influence of Planets
on Disk Observations
(and the influence of disks
on planet observations)
Geoff Bryden (JPL)
Doug Lin (UCSC)
Hal Yorke (JPL)
What kind of disk features
should we expect?
• Planetary Gaps
• Spiral Waves
• Accretional Hot Spots
• Shadowed Regions
• Large Inner Holes?
G. Bryden (JPL)
Effect of Planets on Disk Observations
Computational Method
Computational requirements:
1. hydrodynamics near the planet
2. radiative transfer throughout the disk
3. detailed consideration of the surface heating
 Flux-limited diffusion with stellar ray tracing
This radiative hydrodynamic method is ideal for following the
feedback between disk structure and stellar irradiation.
G. Bryden (JPL)
Effect of Planets on Disk Observations
Model Parameters
G. Bryden (JPL)
Effect of Planets on Disk Observations
Axisymmetric Disk (no planet)
T
ρ
G. Bryden (JPL)
Effect of Planets on Disk Observations
Axisymmetric Disk (no planet)
T
ρ
G. Bryden (JPL)
Effect of Planets on Disk Observations
Axisymmetric Disk (no planet)
T
ρ
G. Bryden (JPL)
Effect of Planets on Disk Observations
Temperature v.s. Radius
Midplane Temp.
Surface Temp.
(ChiangGoldreich power-law)
G. Bryden (JPL)
Effect of Planets on Disk Observations
Gap-Opening, Jupiter-Mass Planet
(side view)
T
ρ
G. Bryden (JPL)
Effect of Planets on Disk Observations
Temperature v.s. Radius:
with/without a gap
No Gap
Gap
G. Bryden (JPL)
Effect of Planets on Disk Observations
Spectral Energy Distributions
SED components
with/without a gap
v.s. Inclination
G. Bryden (JPL)
Effect of Planets on Disk Observations
Observing Gap Formation with ALMA
Wolf et al. 2002
• Jupiter-mass planet at 5.2 AU
• 0.7mm images
4 hour integration on ALMA
G. Bryden (JPL)
Effect of Planets on Disk Observations
Embedded, Neptune-Mass Planet
(side view)
T
ρ
G. Bryden (JPL)
Effect of Planets on Disk Observations
Embedded Planet:
1AUx1AU View of the Fountain Flow
T
ρ
G. Bryden (JPL)
Effect of Planets on Disk Observations
Space Interferometry Mission
SIM will attempt to detect
the astrometric signal of
young planets just as they
are forming.
G. Bryden (JPL)
Effect of Planets on Disk Observations
Sources of Astrometric Wobble
1. Planet’s Gravitational Pull
2. Disk’s Gravitational Pull
3. Disk’s Photospheric Signal
(center-of-light wobble)
G. Bryden (JPL)
Effect of Planets on Disk Observations
Rotating Gap-Opening Planet
G. Bryden (JPL)
Effect of Planets on Disk Observations
Rotating Embedded Planet
G. Bryden (JPL)
Effect of Planets on Disk Observations
Inner Disk Holes
Inner holes may be caused by:
• Photoevaporation (Clarke)
• Giant planet torques (Wood)
• Dust coagulation
• Planet accretion
• Misinterpreted SED (Boss & Yorke 1996)
G. Bryden (JPL)
Effect of Planets on Disk Observations
SEDs for Disks with Inner Holes
R_in = 0.05 AU
R_in = 100 AU
G. Bryden (JPL)
Effect of Planets on Disk Observations
Spitzer IRAC color excesses
v.s. Inner Hole Size
G. Bryden (JPL)
Effect of Planets on Disk Observations
Summary
(yes, this is the last slide, so pay attention now)
Spitzer observations (IRAC & IRS) can be used to characterize
disks in the planet-forming region around young stars.
In particular, inner disk holes will be identified in this region.
ALMA should easily detect protoplanetary gaps
for Jupiter-like planets. Evidence of embedded
proto-Jupiters (hotspots/extended shadows) is
much more difficult.
SIM will be able to observe young planets, even when surrounded
by a massive disk. This will address key questions such as:
1) where & when giant planets form, 2) how their eccentricity
evolves, and 3) whether their distribution evolves with time.
G. Bryden (JPL)
Effect of Planets on Disk Observations