Observing Gap Opening By Planets
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Observing Gap Opening By Planets Dr. Hannah Jang-Condell Michelson Fellow University of Maryland NASA’s Goddard Space Flight Center September 8, 2010 Jang-Condell
description
Observing Gap Opening By Planets. Dr. Hannah Jang-Condell Michelson Fellow University of Maryland NASA’s Goddard Space Flight Center. Protoplanetary Disks. TW Hya. T Tauri (F,G,K stars) or Herbig Ae /Be (A,B stars) Young (~ 1 Myr ) Optically thick Gas-dominated - PowerPoint PPT Presentation
Transcript of Observing Gap Opening By Planets
Jang-Condell
Observing Gap Opening By Planets
Dr. Hannah Jang-CondellMichelson Fellow
University of MarylandNASA’s Goddard Space Flight Center
September 8, 2010
September 8, 2010
Protoplanetary Disks• T Tauri (F,G,K
stars) or Herbig Ae/Be (A,B stars)
• Young (~1 Myr)• Optically thick• Gas-dominated• Era of Giant
Planet formation
AB Aur
TW Hya
Debes, et al. in prep
HST/STIS
Fukagawa, et al. 2004
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Probing the Epoch of Formation
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Protoplanetary disk
Calculating Observables
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Flared disk
To observer =2/3
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Scattered Light
=2/3
F*
FincF*/r2
Thermally reprocessed: Td
3D RT model
i I = cos Finc
4 (cos +cos i)
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Thermal Emission
=2/3Thermallyreprocessed
dI/dl = B(Td) exp(-)
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Simulated Images
Flared disk
Shorter wavelengths, higher opacities,probe surface layers
Longer wavelengths, lower opacities,probe deeper
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Gap Opening by Planets
• Bate et al., 2003• Gap-opening
threshold: rHill =
(Mcrit/3M*)1/3a = H
• Mcrit = 0.38 MJ
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1 MJ 0.3 MJ
0.1 MJ 10 ME
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Gap Profiles
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Planet mass Width(w)
Depth(d)
80% Mcrit 0.17 a 0.84
27% Mcrit 0.11 a 0.56
8% Mcrit 0.078 a 0.014
€
Σ=Σ0(1− d) ×
exp[−(r − a)2 /2w2]
Bate et al., 2003
0.8 Mcrit
0.08 Mcrit
0.27 Mcrit
2.7 Mcrit
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Aristarchus crater, the MoonCredit: NASA (Apollo 15)
Shadow Feedback
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1/3 Jupiter Mass at 10 AU
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No planet 37 MEarth 110 MEarthGapAt
10 AU
1 μm
30 μm
100 um
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Inclination
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brighter
dimmer
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No planet 37 MEarth 110 MEarth45°Incl.
1 μm
30 μm
100 um
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LkCa 15
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Thalmann et al., 2010
H-band scattered light
(Mulders, et al. 2010)
(Espaillat, et al. 2008)
< 6 MJ
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LkCa 15 models
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Lower mass limit: 1.5 MJ
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LkCa 15 Radio Images
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2.8 mm 1.4 mm
1.3 mm
Piétu, et al. 2006 (IRAM)
Isella, et al. (CARMA)
1.5 MJ
0.5 MJ
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LkCa 15 model SED
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Bigger gaps appear brighter
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TW Hya• 56 AU• Hubble observations
– STIS– NICMOS– 7 wavelengths
• Debes, Jang-Condell, et al. (in prep)
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Multi-wavelength FitFit parameters:• Gap depth
– 30%, 50%• Gap width
– 10, 20, 30 AU• Grain size
– amin 0.005, 0.5, 5 um• Disk truncation
– 60, 80, 100 AU
• Gap depth 30%
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Debes, Jang-Condell, et al., in prep
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Partial Gaps• Gap-opening threshold: – rHill =(Mp/3M*)1/3a = H
• for TW Hya, @ 80 AU: Mcrit = 0.9 MJup
• 30% gap: ~0.3 MJup = Saturn mass
1 MJ 0.3 MJ
0.1 MJ
3 ME
10 ME
1 ME Bate, et al. 2003
rHill~H
50% gap
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TW HyaGap vs. GaplessGap is apparent in the brightness profile from optical to far-IR wavelengths
Thi et al. 2010PACS observations of TW Hya“No extended emission has been found.”
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Summary
• Self-shadowing in gaps enhances the gap depth
• Gaps are detectable in resolved disk images• May be detectable in SEDs also• Can infer planet masses from the observed
gaps sizes
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7 degrees inclinationIsotropic scattering
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