Peering into the Birthplaces of Solar Systems
Early ALMA and EVLA Observations of Circumstellar Disks
K. Teramura UH IfA
David J. Wilner
Harvard-Smithsonian Center for Astrophysics
Atacama Large Millimeter/submillimeter Array
Expanded Very Large Array
Robert C. Byrd Green Bank Telescope
Very Large Baseline Array
From Disks to Planets
Silhouette Disks in Orion Nebula around ~1 Myr-old stars
Planets Orbting HR8799
Marois et al. 2008, 2010
McCaughren & O’Dell 1995
Astro2010: How do circumstellar disks evolve and form planetary systems?
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Relevance of Radio Astronomy
ALMA
EVLA
• 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!
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Next Generation Radio Telescopes
Atacama Large Millimeter Array
• 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
Expanded Very Large Array
• 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
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 Disk
PI 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.
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TW Hya Background
• closest gas-rich ~few Myr-old disk (160 ly)
– isolated, viewed nearly face-on
– southern sky
– many studies with Submillimeter Array
HST, Weinberger et al. 2002
Andrews et al. 2011
Doppler shift
Qi et al. 2004
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TW Hya CO J=3-2 from ALMA
• Keplerian model/data comparison – can you tell the difference?
• 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
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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
• DCN distribution is different!
Qi et al. 2008
Oberg et al. 2012
• evidence for multiple pathways
to deuterium enhancement in disks
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From Dust to Planets
Planetesimal formation
Collisional agglomoration
1mm
1mm
radio spectral
signatures
Planet formation
???
(collective effects)
1m
1km
Gravityassisted
growth
Gas
capture
1000km
Debris
Collisons
<1km
planet-disk
interactions
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Spectral Signatures of Grain Growth
• mm/cm dust emissivity  ~ l-
•  is diagnostic of maximum grain size
previous VLA results
0

“pebbles”

2
ISM grains
see Draine 2006
Rodmann et al. 2006
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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
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(Preliminary) EVLA Taurus Disk Images
Chandler et al, in prep
l = 9 mm (30.5
and 37.5 GHz)
θ ~ 0.7 arcsec
= 100 AU
spectral indices
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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
P. Armitage: jila.coloarado.edu/~pja
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TW Hya: Planet-Disk Interaction
• should be easy to detect with EVLA and ALMA
at the limits of ALMA
Wolf & D’Angelo 2005
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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)
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Fomalhaut with ALMA at 870 mm
ALMA Cycle 0 Reference Image
rmsPI
noise
70 mJymeasure
Boley:
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
1.5” x 1.2”
Boley et al. in prep.
20 arcseconds
~ 150 AU
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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 disks
PIs: 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: interactions
PIs: Jordan, Huelamo, Boley
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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
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