high-resolution disks observations
DESCRIPTION
Gaspard Duchêne UC Berkeley – Obs. Grenoble. High-resolution disks Observations. Outline. The big questions and how to answer them Scattered light imaging ( sub)mm interferometric mapping A few ‘exotic’ approaches Questions still to be solved - PowerPoint PPT PresentationTRANSCRIPT
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
HIGH-RESOLUTION DISKS
OBSERVATIONSGaspard DuchêneUC Berkeley – Obs. Grenoble
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Outline The big questions and how to answer them Scattered light imaging (sub)mm interferometric mapping A few ‘exotic’ approaches Questions still to be solved Future instrumentation and the role of long-
baseline interferometry
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
The big questions Can we empirically constrain the process of
planet formation? What are the successive stages?
What is the structural evolution of disks?Where does planet formation occur?What are the associated timescales?How do disks dissipate?
Which disks will form planets?Important to compare to exoplanets surveys
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
High-resolution techniques Scattered light imaging
Optical: HSTNear-IR (1-5μm): ground-based AORequires coronagraphy: mask central regionsEnables polarization mapping
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
High-resolution techniques Scattered light imaging
Optical: HSTNear-IR (1-5μm): ground-based AORequires coronagraphy: mask central regionsEnables polarization mapping
Thermal emission mapping (submm/mm/cm)SMA, PdBI, eVLA, CARMA, ATCAEnables gas mapping
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
High-resolution techniques Scattered light imaging
Optical: HSTNear-IR (1-5μm): ground-based AORequires coronagraphy: mask central regionsEnables polarization mapping
Thermal emission mapping (submm/mm/cm)SMA, PdBI, eVLA, CARMA, ATCAEnables gas mapping
Explicitly excluding IR interferometry here
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Complementary approaches
Scattered lightPAH imaging
Thermalimaging
IR interferometry
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Outline The big questions and approaches Scattered light imaging (sub)mm interferometric mapping A few ‘exotic’ approaches Questions still to be solved Future instrumentation and the role of
long-baseline interferometry
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Scattered light imagingCourtesy M. Perrin
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Scattered light imaging Image the outer disk surface
Estimate disk size/inclinationProbe the overall flaring geometry
Burrows etal. (1996)
Krist et al.(2000)
TW Hya
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Scattered light imaging Image the outer disk surface
Estimate disk size/inclinationProbe the overall flaring geometryProbe grain size/composition
Honda et al. (2009)
Duchêne et al. (2004)
GG Tau
HD 142527
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Scattered light imaging Image the outer disk surface
Estimate disk size/inclinationProbe the overall flaring geometryProbe grain size/compositionIdentify large-scale asymmetries (nature?)
Fukagawaet al. (2004)
Grady etal. (2001)
AB Aur HD 100546
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Scattered light imaging Polarized imaging is a key asset
It alleviates the contrast problemIt provides physical information that helps
disentangling dust properties from disk structure
Apai et al. (2004)
Oppenheimeret al. (2008)
Silber etal. (2000)
GG Tau
AB AurTW Hya
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Main results from scattering Outer disks are flared, consistent with
hydrostatic equilibrium (good coupling)
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Main results from scattering Outer disks are flared, consistent with
hydrostatic equilibrium (good coupling) Dust grains in the surface are not much
larger than ISMamax ~ 1mm strongly excluded (amax < 10μm)
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Main results from scattering Outer disks are flared, consistent with
hydrostatic equilibrium (good coupling) Dust grains in the surface are not much
larger than ISMamax ~ 1mm strongly excluded (amax < 10μm)
Departures from asymmetry are commonSpiral arms, gaps, dimples…Warp, variable illumination effects
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Limitations of scattering No view of planet-forming region
Masked region: 40-100 AURequires extrapolation inwards
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Limitations of scattering No view of planet-forming region
Masked region: 40-100 AURequires extrapolation inwards
Limited sensitivity to fine-scale structureSpatial resolution: 5-10 AU
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Limitations of scattering No view of planet-forming region
Masked region: 40-100 AURequires extrapolation inwards
Limited sensitivity to fine-scale structureSpatial resolution: 5-10 AU
Ambiguous interpretation of substructuresSurface density features or local H0 features?
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Limitations of scattering No view of planet-forming region
Masked region: 40-100 AURequires extrapolation inwards
Limited sensitivity to fine-scale structureSpatial resolution: 5-10 AU
Ambiguous interpretation of substructuresSurface density features or local H0 features?
Over half of known disks are undetected!No apparent SED criterion for detectability
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Outline The big questions and approaches Scattered light imaging (sub)mm interferometric mapping A few ‘exotic’ approaches Questions still to be solved Future instrumentation and the role of
long-baseline interferometry
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Thermal continuum mapping
Andrews &Williams (2007)
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Thermal continuum mapping Image the outer disk midplane
Estimate disk sizeEstimate extent of grain growth (up to ~cm)
Kitamura et al. (2002) Natta et al. (2007)
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Thermal continuum mapping Image the outer disk midplane
Estimate disk sizeEstimate extent of grain growth (up to ~cm)Image surface density substructures
Piétu etal. (2005)
Hughes etal. (2009)
AB Aur GM Aur
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Thermal continuum mapping Image the outer disk midplane
Estimate disk sizeEstimate extent of grain growth (up to ~cm)Image surface density substructuresConstrain the Σd profile
Andrews &Williams (2007)
Kitamuraet al. (2007)
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Gas mapping Map simple species in warm outer disk
Enable dynamical analysis of central starServe as basis for chemistry modelingConfirm gas/dust coupling in asymmetries
Piétu etal. (2005)
AB Aur
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Main results from mm mapping Best results from highest
spatial resolution Non-power law structure:
Relatively flat overall profileTapered-off outer regionAccounts for gas/dust obs.
Quite different from MMSN! Much like similarity solution
Isella etal. (2009)
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Main results from mm mapping Deficit of dust emission in inner regions
is an unexpectedly common occurrence No counterpart in gas!
Guilloteau etal. (2008)
Isella etal. (2010)
RY Tau
HH 30
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Limitations of mm mapping Limited ability to resolve substructures
Linear resolution: ≥ 30 AU Requires extrapolation inwards
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Limitations of mm mapping Limited ability to resolve substructures
Linear resolution: ≥ 30 AU Requires extrapolation inwards
Innermost region is optically thick
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Limitations of mm mapping Limited ability to resolve substructures
Linear resolution: ≥ 30 AU Requires extrapolation inwards
Innermost region is optically thick Limited sensitivity
Focus on brightest disks for high resolution
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Limitations of mm mapping Limited ability to resolve substructures
Linear resolution: ≥ 30 AU Requires extrapolation inwards
Innermost region is optically thick Limited sensitivity
Focus on brightest disks for high resolution Model-dependent results!
Not enough resolution elements for data to guide modeling (apart from peculiar cases)
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Outline The big questions and approaches Scattered light imaging (sub)mm interferometric mapping A few ‘exotic’ approaches Questions still to be solved Future instrumentation and the role of
long-baseline interferometry
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Some more ‘exotic’ datasets PAH imaging around Herbig Ae stars
Geometry of illuminated outer diskPoorer angular resolution (λ=3-11μm)A proxy to scattering, less contrast-limited
HD 97048PDS 144N
Lagage et al. (2006)Perrin et al. (2006)
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Some more ‘exotic’ datasets Spectro-astrometry of hot gas
Can reach ~1mas resolutionCO detected in most disks!
Gas found within inner holes Enables dynamical studies
Pontoppidanet al. (2008)
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Some more ‘exotic’ datasets Time domain: periodic occultation
Can probe all the way to the inner radiusWarp/wall in innermost diskCan probe long-term dynamics
Occurrence rate: ~30% !?
Bouvier et al.(1999, 2007)
P=8.2d
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Outline The big questions and approaches Scattered light imaging (sub)mm interferometric mapping A few ‘exotic’ approaches Questions still to be solved Future instrumentation and the role of
long-baseline interferometry
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
How about the inner disk?? The formation zone of most known
exoplanets is believed to be <10 AU What is the structure of disks on that scale? How do the inner and outer disk relate to
each other? How bad are the current extrapolations?
What is the link between planet formation and disk dissipation?
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
How about the inner disk?? Some predictions/hypotheses to be tested:
Accretion geometry on central star/binaryPuffed-up rim and associated shadowed regionGas within the inner rimPlanet-induced gapsSnow line with pile-up of larger grains/bodiesEmpty (?) holes in transition disksRole of inner disk for undetected outer disks
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
How about the inner disk?? Some predictions/hypotheses to be tested:
Accretion geometry on central star/binaryPuffed-up rim and associated shadowed regionGas within the inner rimPlanet-induced gapsSnow line with pile-up of larger grains/bodiesEmpty (?) holes in transition disksRole of inner disk for undetected outer disks
We need to image the inner disk
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Outline The big questions and approaches Scattered light imaging (sub)mm interferometric mapping A few ‘exotic’ approaches Questions still to be solved Future instrumentation and the role of
long-baseline interferometry
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Future instrumentation Next Generation AO on 8-10m telescopes
NICI, SPHERE, GPI, HiCIAO, …Same resolution, much higher contrastLimited to the brightest young starsRegion within 10-20 AU still blocked out
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Future instrumentation Next Generation AO on 8-10m telescopes
NICI, SPHERE, GPI, HiCIAO, …Same resolution, much higher contrastLimited to the brightest young starsRegion within 10-20 AU still blocked out
AO on 30-40m telescopes (E-ELT, TMT, …)Higher resolution (~2 AU)Uncertain image qualityPlanet-forming region still out of view (?)
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Future instrumentation ALMA
Much higher spatial resolution (~0.5 AU)Much improved image fidelityInnermost regions optically thick, especially at the
shortest wavelengths (best resolution)
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
Future instrumentation ALMA
Much higher spatial resolution (~0.5 AU)Much improved image fidelityInnermost regions optically thick, especially at the
shortest wavelengths (best resolution) JWST
PSF stability enables HST-like work in the mid-IRProbe of 1-10μm dust grains (rarely doable now)Limited spatial resolution (~40 AU)
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
The realm of interferometry For most disks: 0.15 AU ≅ 0.001”
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
The realm of interferometry For most disks: 0.15 AU ≅ 0.001” Large number of baseline critical Many beams across the image needed
We need empirically-based input to improve our general understanding and detailed modeling
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
The realm of interferometry For most disks: 0.15 AU ≅ 0.001” Large number of baseline critical Many beams across the image needed
We need empirically-based input to improve our general understanding and detailed modeling
Large dynamical range required
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
The realm of interferometry For most disks: 0.15 AU ≅ 0.001” Large number of baseline critical Many beams across the image needed
We need empirically-based input to improve our general understanding and detailed modeling
Large dynamical range required Sensitivity key to survey broad samples
Gaspard Duchêne - Circumstellar disks and planets - Kiel - May 26-28 2010
The realm of interferometry For most disks: 0.15 AU ≅ 0.001” Large number of baseline critical Many beams across the image needed
We need empirically-based input to improve our general understanding and detailed modeling
Large dynamical range required Sensitivity key to survey broad samples Inner disk midplane is out of reach!
Optically thick at all wavelengths