peering into the birthplaces of solar systems atacama large millimeter/submillimeter array expanded...
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Peering into the Birthplaces of Solar Systems
Atacama Large Millimeter/submillimeter ArrayExpanded Very Large Array
Robert C. Byrd Green Bank TelescopeVery Large Baseline Array
Early ALMA and EVLA Observations of Circumstellar Disks
David J. WilnerHarvard-Smithsonian Center for Astrophysics
K. Teramura UH IfA
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From Disks to Planets
Astro2010: How do circumstellar disks evolve and form planetary systems?
McCaughren & O’Dell 1995
Marois et al. 2008, 2010
Silhouette Disks in Orion Nebula around ~1 Myr-old stars
Planets Orbting HR8799
AAAS, February 2012
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Relevance of Radio Astronomy • avoid high dust
opacities mass tracer
• many spectral lines diagnostics, kinematics
• sensitive to cold material including mid-plane
• contrast with star planet-forming region
• high sensitivity and angular resolution ALMA and EVLA!
ALMA
EVLA
AAAS, February 2012
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Next Generation Radio Telescopes
• 66 moveable 12m/7m antennas 5000 m site in northern Chile l = 300 mm to 3 mm
• global collaboration (NA, EU, EA) to fund >$1B construction
• 27 moveable 25 m antennas 2000 m site in New Mexico l = 7 mm to 4 m
• modern electronics and signal processing, c. 1980 infrastructure
Atacama Large Millimeter Array Expanded Very Large Array
AAAS, February 2012
10-100x better sensitivity, spectral capabilities, resolution
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Some Early Disk Observations
• ALMA Science Verification: TW Hya Protoplanetary Disk
test system validity, data released to community
• disks@EVLA key project: Grain Growth and Structure
PI Claire Chandler (NRAO) and 17 co-I’s worldwide
• ALMA Early Science: Fomalhaut Debris DiskPI Aaron Boley (U. Florida) and 5 co-I’s
These results already showcase the extraordinary science potential of the new radio telescopes.
Many more amazing observations are underway. AAAS, February 2012
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HST, Weinberger et al. 2002
TW Hya Background • closest gas-rich ~few Myr-old disk
(160 ly)– isolated, viewed nearly face-on – southern sky– many studies with Submillimeter
Array Andrews et al. 2011
Qi et al. 2004
Doppler shift
AAAS, February 2012
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TW Hya CO J=3-2 from ALMA
• Keplerian model/data comparison – can you tell the difference?
AAAS, February 2012
• incredible data (from a small fraction of ALMA)!
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TW Hya DCN J=3-2 from ALMA• imaging a deuterated, nitrogen-bearing, triatomic
molecule (!)• Earth’s oceans
are enriched in deuterium
• deuteration is associated with low temps:
H3+ + HD
H2D+ + H2 + DE
• water delivery from cold, outer Solar System? (by comets)
Hartogh et al. 2011
AAAS, February 2012
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TW Hya DCN J=3-2 from ALMA• SMA DCO+: D/H enhancement at large disk radii
– supports in situ deuteration at low T in outer disk
• water delivered from cold, outer Solar System?
• evidence for multiple pathways to deuterium enhancement in disks
• DCN distribution is different!
Oberg et al. 2012
Qi et al. 2008
AAAS, February 2012
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radio spectral signatures
From Dust to Planets
planet-disk interactions
1mm 1mm 1m 1km 1000km <1km
Planetesimal formation Planet formation
Collisional agglomoration
Gravity-assistedgrowth
Gascapture
??? (collective
effects)
Debris
Collisons
AAAS, February 2012
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Spectral Signatures of Grain Growth• mm/cm dust emissivity ~ l-
• b is diagnostic of maximum grain size
b
AAAS, February 2012
see Draine 2006
Rodmann et al. 2006
ISM grains“pebbles”2
b0
previous VLA results
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Disks@EVLA Key Project• (PI Chandler) grain growth and substructure in
protoplanetary disks: last observable link in chain from ISM to planets
1. photometry of 60+ disks at 7/9/13/50 mm– spectral indices reveal large grains– reduction and modeling underway
2. imaging of subsets, to 50 mas = few AU– surface densities, disk-planet interactions– observations ongoing– expect resolved mm/cm colors
K. Teramura UH IfA
AAAS, February 2012
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(Preliminary) EVLA Taurus Disk Images
spectral indices
l = 9 mm (30.5 and 37.5 GHz)
θ ~ 0.7 arcsec = 100 AU
Chandler et al, in prep
AAAS, February 2012
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P. Armitage: jila.coloarado.edu/~pja
TW Hya: Planet-Disk Interaction• giant planet opens disk gap and creates cavity• 4 AU radius cavity (barely) detected with VLA
Hughes et al. 2007
AAAS, February 2012
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TW Hya: Planet-Disk Interaction• should be easy to detect with EVLA and ALMA
at the limits of ALMAWolf & D’Angelo 2005
AAAS, February 2012
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Fomalhaut Background• ~200 Myr-old nearby star (25 ly) with
dusty debris• directly imaged orbiting planet possible circumplanetary disk?
Kalas et al. (2008)
AAAS, February 2012
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Kal
as e
t al
. (2
009)
PI Boley: measure thermal dust emission from known circumstellar material and potentially circumplanetary dust near Fomalhaut b using the compact (3 hrs) and extended early science antenna configurations
Fomalhaut with ALMA at 870 mm
AAAS, February 201220 arcseconds ~ 150
AU
Boley et al. in prep.
ALMA Cycle 0 Reference Imagerms noise 70 mJy
1.5” x 1.2”
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Underway in ALMA Cycle 0…
• young disks: Orion, brown dwarfs, binaries, chemistry, gas/dust structure, dynamics
PIs: Mann, Akeson, Ricci, Qi, Lin, Carpenter, Salyk, Chapillon, Walsh
• old disks: debris, birth rings, Herschel cold disksPIs: Rodriguez, Jordan, Carpenter, Boley, Wilner, Woitke
• in-between disks: gas-poor/dust-rich, gas-rich/dust-poor, gas in cavities, dust in cavities, unusually small/large disks
PIs: Dutrey, Andrews, Chapillon, Casassus, van Dishoek, Perez, Schreiber, Kospal
• disks and planets: interactionsPIs: Jordan, Huelamo, Boley
AAAS, February 2012
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A new “Radio Era” for Disk Studies• large samples of planet-forming disks now within
reach• major unknown is distribution/evolution of cold
dust and gas at Solar System scales: key observables for ALMA and EVLA
• amazing prospects• expect surprises!
at the limits of ALMA
AAAS, February 2012
20AAAS, February 2012
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