ALMA Science Advisory Committee Teleconference, 3 July 2002 Draft Minutes Participants: A. Benz, G. Blake, R. Booth, L. Bronfman, J. Conway, P. Cox, R. Crutcher, N. Evans, S. Guilloteau, M. Gurwell, M. Ishiguro, R. Kurz, R. Kawabe, R. Lucas, J. Mangum, D. Mardones, H. Matsuo, L. Mundy, M. Rafal, S. Sakamoto, P. Schilke, P. Shaver, K. Tatematsu, P. Vanden Bout, C. Wilson, A. Wootten, S. Yamamoto, M. Yun The proposed agenda was adopted, and the minutes of the June teleconference were accepted. 1) Status Report P. Vanden Bout said that recent meetings of the ACC have focussed largely on the issues in Chile. He described the activities of the newly formed Joint ALMA Office. The focus over the past month has been on planning and discussions in Chile. He and the interim Project Manager M. Tarenghi studied the site issues, and arrived at two options, (a) OSF located along the main highway, and (b) OSF located south-east of San Pedro, on a dedicated ALMA access road. The latter option is much preferred, and the ACC agrees with this preference. The coordinates of both the ALMA site and the OSF location have now been fixed. P. Vanden Bout and M. Tarenghi also had several meetings with officials in Chile: the Ministry of Foreign Affairs and its legal department, CONICYT and the Chilean astronomers, Biennes Nacionales, and authorities in Region II. The working group (Vanden Bout, Brown, Hardy, Hofstadt) has continued these efforts. On July 1 the ALMA negotiating team met with the Foreign Ministry and others. The meeting went well, and there were three issues left: (a) the question of whether ESO=92s operation of a new site requires the approval of the Chilean parliament, (b) how future unrelated projects on the ALMA site will be treated (and whether the ALMA project will have a say), and (c) what benefits the ALMA project should give to Chile and its astronomers. A further meeting is planned later in July, and it is then expected that agreements will be signed with the various parties. The concession for the site is planned to have a duration of 50 years. It is hoped that access to the site will be secured by the end of the year. The environmental impact studies will start now, and will hopefully be completed by early 2003. L. Bronfman mentioned that the eastern half of the science preserve (to the east of the Y++ configuration) will be held by CONICYT, and possible future antennas added to the array might be placed there. R. Kurz reported on the AMAC meeting of 24-25 June. The AMAC urged that the final approvals for the project be made as soon as possible. They applauded the formation of the Joint ALMA Office. Their recommendations and requests included the following: the permanent key personnel should be appointed as soon as possible; the Joint Project Office should include all four persons; the complete detailed project plan should be provided by January 2003; other options should be provided for the production antennas; and clarification on the planning of the frontends, which were identified as being on the critical path, was required. The good progress being made on the Vertex prototype antenna was summarized by A. Wootten. Finally, P. Cox mentioned the imminent decision on ALMA to be made at the ESO Council meeting next Monday and Tuesday (8-9 July). 2) Charges from the ACC to the ASAC Progress reports were made on each of the four charges from the ACC to the ASAC: a) Site evaluation and stringency N. Evans reported that the group (S. Radford and student, R. Lucas, J. Richer, C. Wilson, D. Mardones, and N. Evans) had decided that the starting point was the concept of stringency, considering in particular the following three parameters: opacity, phase stability and pointing accuracy. The studies were underway. The group will keep in close contact with the Early Science group. b) Long baseline Y+ configuration J. Conway compared the merits of the Y+ configuration with the ring configuration. The Y+ configuration saves resources (pads, roads, fibers etc), gives more intermediate configurations, and can provide longer baselines =96 up to 19 km (limited by the highway to the north and the volcanoes to the south). He stressed that astrometry is critical. A. Wootten added that the imaging performance is being evaluated. c) Enhancements to the baseline ALMA instrument The possible enhancements proposed by the Japanese astronomical community were summarized by S. Yamamoto. They are as follows: (1) The ACA. This includes twelve 7-meter antennas and four 12-meter antennas with cryo systems, baseline-receiver cartridges, IF and backend systems. The four 12-meter antennas are used for calibrating the ACA and also for accurate single-dish measurements. This will enhance the imaging capability of ALMA. (2) New receiver bands: bands 8, 10 and 4, with receiver cartridges for 64 baseline antennas and 16 ACA antennas. This particularly enhances the submillimeter-wave capability of ALMA. (3) A second generation correlator: high resolution correlators for the 64+16 antennas. This enhances the spectroscopic capability of ALMA. (4) Contribution to infrastructure. NAOJ is making its best efforts to obtain a budget to achieve a value very close to the level of 1/3 of a trilateral ALMA project, in order to cover all the enhancements listed above. The production of the antennas of the ACA, i.e. four 12-meter and twelve 7-meter antennas, together with the enhancement of submillimeter-wave capability, are considered as being strategically important items in the Japanese budget request. These possible enhancements have not yet been finally approved by the ALMA-J project, and are still under discussion. M. Ishiguro stressed that this proposal is a current =93working model=94, for discussion with = the ministries. He said that tough discussions and negotiations are currently going on with MEXT, which will issue a report at the end of the year, and that help from the ASAC would be useful. C. Wilson commented that the list of proposed enhancements seemed somewhat large compared to what was being proposed a year ago, and S. Yamamoto explained how Japan expected to be able to fit these enhancements into the budget. He and M. Ishiguro commented that it was important to produce 12-meter antennas, in view of the prototype already being built, and that all the proposed enhancements fitted well into an overall concept to further develop Japanese mm astronomy beyond Nobeyama and to enhance ALMA=92s performance particularly in the submm domain. d) Early science with ALMA On this topic, P. Cox referred to the e-mails which had recently been distributed, and requests further input from ASAC members, to be sent to the ASAC mailing list. He proposed that the Early Science working group get together via teleconference, and then send an e-mail to all ASAC members. There was a brief discussion about the possibility of making early observations at high frequency. P. Cox and G. Blake felt that it would be difficult to start at high frequency, and S. Guilloteau said that this approach could delay the overall suite of receivers. D. Mardones commented that the ACC charge did not mention timescale, and said that the early science with ALMA will obviously ramp up over time, through different stages. 3) Software status report R. Lucas reported that the software requirements are currently being reviewed, and that the focus at present is on the requirements from last year. An audit of AIPS++, to determine whether each software requirement is fulfilled by AIPS++, is being carried out by Meyers, Viallefond and Morita. A first report will be made to the ASAC in September. A benchmarking process, setting benchmarks for AIPS++, will take longer than September. Concerning the status of the AIPS++ tests at IRAM, R. Lucas reported that they are running late. Phase 1 will be completed in a few weeks, and Phase 2 (applying AIPS++ to other data sets) has not yet started. It is hoped to be able to report on both at the September meeting. 4) Draft agenda for and organization of the ASAC face-to-face meeting The draft agenda of the September face-to-face meeting was briefly discussed. C. Wilson suggested that the configuration work be added. P. Cox requested that comments on the agenda be sent to him, with a copy to A. Wootten. Practical details about the meeting will be distributed to ASAC members by A. Wootten. 5) Next teleconference The next ASAC teleconference will take place on Wednesday 7 August at 14:30 UT. ---------------------