Teleconference, 23 August 2001

Draft Minutes

Participants: R. Bachiller, A. Benz, G. Blake, R. Brown, P. Cox, R.
Crutcher, N. Evans, F. Gueth, M. Gurwell, T. Hasegawa, M. Hogerheijde,
R. Kawabe, R. Lucas, J. Mangum, H. Matsuo, R. Kurz, M. Rafal, J. Richer,
S. Sakamoto, P. Schilke, P. Shaver, K. Tatematsu, E. van Dishoeck, C.
Wilson, A. Wootten, M. Yun

The proposed agenda was adopted, and the minutes of the last
teleconference were accepted following two revisions proposed by E. van
Dishoeck.

1. Update on three-way project

R. Brown expressed optimism that the U.S. will approve construction for
the fiscal year beginning 1 October , 2001. He also said that the 26
July meeting with Chilean authorities had been very positive, with
strong goodwill expressed for the project and future steps defined. The
EAEC is working on the 3-way project definition and development. A
meeting will be held in Charlottesville next week; a draft will be
available in time for the ASAC meeting, and by 1 October the 2nd
iteration will be complete. Progress has been made on the procurement
plans for the production antennas. T. Hasegawa said that the situation
in Japan was as reported in the last telecon.

2. Report ACA, science examples, text science case

A. Wootten said that various science cases are being studied, and new
algorithms are being developed for simulations. F. Gueth commented on
the status of simulations at IRAM; they are ready to start new
simulations now, with an improved simulator and a newly developed
deconvolution method. Previous cases will be re-run, as well as new
ones. R. Crutcher commented that the plan should be to have 3 cases
compared: (1) ALMA + single dish + ACA, (2) ALMA + single dish, and (3)
ALMA alone. F. Gueth said that the ACA (taken to mean 12 x 7m antennas)
does provide a significant improvement in the interpolation between the
single dish and ALMA. But then it depends on the actual science cases,
and the deconvolution techniques. A. Wootten said that the results
should be ready for the ASAC meeting in Chile. R. Brown commented that
it was important to keep in mind how the case would be made to the EACC,
focussing on the possible improvement in the science that may be
provided by the ACA.

The science cases were briefly reviewed. M. Yun is studying the example
of M51 (arm/interarm contrast, line ratios etc). He commented that there
should be an agreed set of tests. M. Hogerheijde is working on the case
of a protostar embedded in an envelope, and finds that the derived line
ratios are a critical test. A. Wootten is studying the Mundy
protoplanetary disk model; recovery of the faint outer rings will be an
important test. R. Crutcher is working on a turbulent cloud model. M.
Holdaway will provide simulations with MEM. A. Wootten said that
writeups of these analyses will be done by 1 September, and on the web
by 4 September.

3. Report operations working group; statement of work

N. Evans said that a draft document has been produced by the WG, and was
discussed in a WG telecon an hour ago. Issues include flexibility of the
system for observations inputs, relative weighting of the criteria for
flexible scheduling (execution status, stringency, and scientific
ranking), and the possible roles of the Regional Data Centers. The
revised draft will be available by 30 August.

4. Report SSR Berekely meeting

R. Lucas reported that this meeting produced a new version of the
scientific software requirements. A draft will be available by the end
of next week.

5. Chile site visit agenda

E. van Dishoeck reminded ASAC members to address any specific questions
about the site visit to the organizers (link).

6. Chile ASAC draft agenda

E. van Dishoeck asked for comments on the draft agenda. C. Wilson
queried the time available for the discussion of calibration issues.
Calibration will obviously be a major part of the ACA discussion, and
other calibration issues may be discussed on the second day. C. Wilson
also requested that only readings relevant to the current ASAC meeting
should be included in the agenda, and this was agreed. R. Kurz suggested
that operations be discussed only in the context of the Operations WG,
as there were no other new developments, and this was also agreed.

7. Science Day

G. Blake agreed to give the concluding talk, replacing J. Welch who will
be unavailable due to teaching commitments.

8. Next teleconference

The date and time of the next ASAC teleconference will be decided at the
ASAC face-to-face meeting.