eSMA: the SMAJCMTCSO array David J' Wilner HarvardSmithsonian CfA

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eSMA the SMA-JCMT-CSO arrayDavid J.
Wilner(Harvard-Smithsonian CfA)

• HIA (Sub)Millimeter Observing Techniques Summer
  School
• August 14-17, 2006

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What is the SMA?

• The SMA is a pathfinding instrument comprised of
  eight 6 meter antennas on Mauna Kea, HI, designed
  for high spatial and spectral resolution imaging
  in submillimeter atmospheric windows.
• The SMA is now being used to study Solar System
  bodies, protoplanetary disks, star forming
  regions, evolved star envelopes, the Galactic
  Center, nearby galaxies, and ultraluminous
  galaxies at cosmological distances.
• The SMA is a collaborative project of the
  Smithsonian Astrophysical Observatory, part of
  the Harvard-Smithsonian Center for Astrophysics,
  and the Academia Sinica Institute of Astronomy
  and Astrophysics (Taiwan)

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SMA and Pupuliahu
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Historical Perspective

• 1984 SAO Study
• (1992-1998 CSO-JCMT)
• 1994 OSDA U. Hawaii
• 1996 ASIAA expansion
• 2 antennas (to 28 baselines)
• 1999-2003 antennas deployed to Mauna Kea
• 2001 JCMT MOU (aim 2005)
• 2004 first SMA science
• 2006 gt50 refereed papers

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SMA Specifications (and why)
Specifications

• Antennas 8 antennas of 6 m diameter, 12
  ?m rms surface
• cost imaging speed
  collecting area (JCMT)
• Configurations 24 pads in four rings
• baseline lengths 8 - 508 m,
• subarcsecond resolution,
  best 0.1
• Receivers max 8 per antenna 2
  simultaneously
• full frequency coverage of
  atmospheric windows
• dual polarization high
  low for calibration
• 177-256 GHz (8 in
  operation)
• 256-360 GHz (8 in
  operation)
• 320-420 GHz (start 2006),
  420-520 GHz (future?)
• 600-720 GHz (8 in
  operation)
• 780-920 GHz (future?)
• Correlator 2 GHz bandwidth, up to 25 kHz
  resolution
• sensitivity, span/resolve
  extragalactic/galactic lines

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Receiver Bands/Atmosphere
460 GHz
230 GHz
345 GHz
690 GHz
805 GHz
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Antenna Stations

• 4 Nested Rings (Keto 1997)
• 4 Configurations
• Subcompact
• Compact
• Extended
• Very extended

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Field of View/Resolution
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SMA Correlator
LSB 2 GHz 24x82 MHz
USB 2 GHz
24x82MHz
10 GHz
e.g. Orion-KL, Beuther et al.
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Spectral Coverage/Resolution
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Observing Information

• SMA partner fractions CfAASIAAIfA 721513
• 20 of CfA time available to PIs from
  worldwide astronomical community w/CfA
  collaboration
• proposal deadlines on 6 month cycle
  (March/September)
• next deadline Sep 7, 2006 (for Nov-Apr)
• last deadline 80 proposals, 8/31 external PI
  proposals rated A
• multiple antenna configurations available
• dynamic queue scheduling according to weather
• RTDC archive, data in public domain after 15
  months
• Calibration and Imaging
• MIR (OVRO)/Miriad and Miriad/AIPS

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http//sma1.sma.hawaii.edu
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http//sma1.sma.hawaii.edu

• SMA Observer Center
• Current Call for Proposals
• Updated Status of Array Technical Capabilities
• Proposal Submission Facility
• Tools
• Beam Calculator/Sensitivity Estimator
• Passband Visualization
• Submillimeter Calibrator List and Flux History
• Link to RTDC Archive Search

One Stop Shopping for All Your SMA Needs
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Beam Calculator/Sensitivity Estimator
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Beam Calculator/Sensitivity Estimator
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Passband Visualizer
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Submillimeter Calibrator List
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What is the eSMA?

• the eSMA is a collaboration between the SMA, the
  JCMT, and the CSO, to join all three
  observatories into a single interferometer array
• will operate part-time in 345 GHz atmospheric
  window

JCMT 15m CSO 10.4m
SMA 8x6m
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Why? I. More Sensitivity

• JCMT and CSO double the array collecting area
• for each baseline
• point source sensitivity
• full track, dual pol, 345 GHz, pwv 1mm, dec 30

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Why? II. More Resolution
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Why? II. More Resolution

• JCMT pad 25
• CSO pad 26
• longest baseline 508 ? 781 m
• uniform weight beam _at_345 GHz 0.31
  x 0.18 (49o)

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eSMA Testing

• 2005 May SMA IF/LO equipment to JCMT
• 2005 Jul first fringes SMA-JCMT (3C454.3)
• 2005 Sep SMA IF/LO equipment to CSO
• 2005 Oct first fringes with SMA-JCMT-CSO
• 2005 Dec attempt to measure baselines
• 2006 new receivers (to be) deployed
• SMA 320-420 GHz, enables 2 pol. 320-355 GHz
• JCMT refurbish RxW, 345 band, 2 pol, IF 4-6 GHz
• CSO new 280-420 GHz, 1() pol, IF 4-6 GHz
• 2007? science observations

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First Fringes SMA-JCMT (267 GHz)
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SMA-JCMT Orion-KL Spectra

• LSB (221-222 GHz) USB (230-231 GHz)

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A few eSMA Issues

• different sky rotation of polarization
• baseline non-intersection of axes terms
• interfaces for SMA control of JCMT and CSO
• JCMT and CSO phase stable? (slew, focus, )
• correlator modes
• 8 SMA CSO JCMT 45 baselines (1 pol)
• 6 SMA CSO JCMT 28 baselines (2 pol)
• eSMA baselines are all long (subarcec)
• implications for SMA configuration(s)?
• politics of time allocation

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eSMA Outlook

• no insurmountable technical problems (yet)
• on track for science observations in 2007
• a lot of exciting science
• opportunities to get involved

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Key People

• SMA Director............. Ray Blundell
• Technical...................... Bob Wilson
• Operations (Hilo)....... Ant Schinckel
• ASIAA........................ Paul Ho