circumstellar disks: what can we learn from alma?
DESCRIPTION
Circumstellar disks: what can we learn from ALMA?. March 2011 - ARC meeting, CSL. 1. Now. ALMA site - January 2011. ARC meeting - March 2011. 2. In 2013. ARC meeting - March 2011. 1. - PowerPoint PPT PresentationTRANSCRIPT
Circumstellar disks: what can we learn from ALMA?
March 2011 - ARC meeting, CSL
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ALMA site - January 2011
Now
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In 2013
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What is ALMA? • ALMA will be the world’s largest interferometer for
millimetre and sub-millimetre wavelengths
• It is in full construction in the Atacama desert
• Collaboration between ESO, NRAO, and NAOJ
• Three sites in Chile
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ALMA specifications • 54 12-m antennas,12 7-m antennas, at 5000 m site• 192 antenna stations• Array configurations between 150 m and ~15-18 km• Angular resolution ~40 mas at 100 GHz (5 mas at 900
GHz)• 10 bands in range 31 to 950 GHz (350-7000 µm)• Dual polarization• ALMA vs Herschel (3.5 m)• Wavelengths: 350 – 7000 µm vs 70 – 550 µm• Angular resol: 1‘ – 0.01“ vs 6“– 35“ • Lifetime : 30 years vs 3.5 years
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Status February 2011 • 8 antennas on site 5000m site and working as interfer.• Fringes observed in 4 bands• Phase closure achieved• ~30 antennas delivered to site in total
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Main science goals • Detect and map CO and [C II] in a Milky Way galaxy at
z=3 in less than 24 hours of observation
• Map dust emission and gas kinematics in proto-planetary disks
• Massive stars (wind acceleration, photosphere,…)
Provide high fidelity imaging in the (sub)millimeter at 0.01 arcsec resolution
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First results
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First results
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Early science
• When?• Call in early April, deadline 8 weeks after• Observations: Fall 2011
• What?• 16 antennas, 2 compact configurations• Bands 3, 6, 7 and 9 (3mm, 1mm, 0.85mm, 0.45mm)• Baselines up to 250m (maybe 500m)• At most 30% of the available time for the first call• Only service mode• Typical project for ES should be few hrs (4-10) and deliver
result!
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Early science
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Early science
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Circumstellar disks
• Imaging protoplanetary disks• Accretion, rotation and outflow• Molecular gas content, chemistry and removal mechanisms• How gaps are created by planets
• Imaging debris disks• Dust evolution, radial dependence of grain properties• Following planets with dust rings
• Probe the growth of dust in disks and constrain planet formation theories
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Circumstellar disks
1 AU
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Imaging proto-planets
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Imaging proto-planets
D’Angelo et al. 2002
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Debris disks
• Optically thin dust in thermal equilibrium with the star :• traces mass of debris or infer mass of comets• shows scale of planetary system
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Early Science Herschel
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Debris disks
• Optically thin dust in thermal equilibrium with the star :• traces mass of debris or infer mass of comets• shows scale of planetary system
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Early Science Herschel
Connection?
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Debris disks
• Dust trapped in resonances by migrating planets in disk
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Debris disks
• Content of residual gas in debris disks• Deep spectroscopy• Comet collisions should evaporate H2O, CO• Method to study exo-comet composition
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ALMA is coming !