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

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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

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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

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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