Agenda for meeting Tuesday, 21 Aug 2001 at 4pm EDT.
Date: 21 Aug 2001
Time: 4:00 pm EDT (2:00 pm Socorro, 1:00 pm Tucson)
Phone: (434)296-7082 (CV SoundStation Premier Conference phone).
Past minutes, etc on MMA Imaging and Calibration Division Page
Minutes
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News from my point of view.
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The ASAC meeting is on Thursday. The agenda is ready.
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The ALMA ACA Tiger Team France is awaiting MEM simulations I guess, a teleconference was held on Friday 10 Aug. Minutes are under construction. http://iraux2.iram.fr/~alma/ has details.
Preliminary conclusions:
1. ALMA+ACA+Single-dish always give much better results on the fidelities in the uv range 0-15 m, whatever the errors we introduce.
2. For sufficiently large errors, all methods give the same results for uv range larger than 20 m. This actually happens for phase errors larger than 40-50 degrees, pointing errors larger than 8 % of the beamwidth, and/or amplitude errors larger than 7-10 %.
3. Typical image plane fidelity for pixels above 3 % of the peak is 35 in case of ``typical'' errors (Phase 40 degrees, Pointing 3 %).
4. Anomalous refraction has negligible effect (compared to the phase noise) on the interferometric data. Its effect on the single-dish data depends on the observing technique.
Al distributed images to ASAC science team and has gotten little response.
Debris Disk Simulation
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ftp.astro.umd.edu. The files (debris.fits and debris.caption) are located in pub/lgm.
This is a simulation of a modestly bright debris disk at a distance of 12 pc around a sun-like star. The total emission is 10 mJy at this observing frequency, 345 GHz. The disk inner radius is 2 AU; the outer radius is 100 AU. The mass of the disk corresponds to roughly 0.4 lunar masses of dust, or 0.5 Earth masses of gas plus dust assuming a gas-to-dust ratio of 100.
Other details of the model are summarized below.
Disk inner and outer radius (in AU) = 2, 100
Dust Temp at 1 au (in Kelvins) = 350
Dust temp power-law index, q = 0.45
Lower limit to allowed temp in disk = 20 K
Surface density power-law index = 1.3
Inclination angle of disk (0=face-on) = 45 deg
Distance to source (in pc) = 12
Position angle of disk (0 = vertical= major axis along dec axis) = 90
Freq of observation in GHz = 345
Location and nature of disk surface features:
1.0 7. 2.0 : dark ring of amp zz, at radius xx AU, width yy AU
2.0 16. 4.0 : dark ring of amp zz, at radius xx AU, width yy AU
1.5 40. 5.0 45. : planet debris of amp zz, at radius xx AU, width yy AU, PA
3.0 60. 9.0 155. : planet debris of amp zz, at radius xx AU, width yy AU, PA
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A face to face E-AEC meeting occurs in Charlottesville 27-29 August.
The next ACA meeting will be on 4 Sep. And of course, the ASAC meeting on Thursday.
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Travel
Oh, always
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