Report of 63rd meeting of the SAC
Toulouse, France, 26-27 May 2003

Recommendation # 1 - Scheduled 2003B GRIF runs
Recommendation # 2 - Possible sale of the CFH12K camera
Recommendation # 3 - MegaPrime hardware component
Recommendation # 4 - Identify and review large and/or long-term WIRCAM projects
Recommendation # 5 - Operations plan for WIRCAM
Recommendation # 6 - Detector of choice for ESPaDOnS
Recommendation # 7 - Design for an ESPaDOnS thermal enclosure
Recommendation # 8 - ESPaDOnS micro lenses
Recommendation # 9 - Pueo Nui for presentation at the next SAC meeting
Recommendation #10 - Communication between the CFHTLS Steering Group and member communities
Recommendation #11 - Duplicate observations in QSO
Recommendation #12 - CFHT User’s Meeting

The meeting was attended by SAC members P. Bastien, J.-L. Beuzit, D. Bohlender (chair), C. Ftaclas, G. Mitchell, P. Petitjean (vice-chair), C. Pritchet, G. Soucail, and B. Tully. E. Emsellem was unable to attend. KAO representative H. Kim was present as an observer. C. Veillet and J.-C. Cuillandre participated in presentations and discussions. Additional presentations were given by J.-F. Donati, Y. Mellier, and L. Domisse. D. Salmon cancelled his attendance because of technical problems with MegaPrime just prior to departure from Hawaii.


Agenda Items:

  1. Welcome new E.D. (SAC)
  2. Technical activities report, including DEC oscillations and GRIF concerns (Salmon)
  3. Instrument and Project reports
    1. MegaPrime status and commissioning activities (Veillet)
    2. WIRCAM
      1. Instrument status (Salmon)
      2. SG report, surveys, filter selection (Beuzit)
    3. ESPaDoNS (Salmon/Donati)
      1. Project status, schedule, commissioning
    4. Pueo Nui (Lai/Cuillandre)
      1. Status
      2. Workshop summary
    5. ‘Ohana (Lai)
      1. Status
      2. Operations model
      3. Sensitivity limits
    6. CFHT environmental data (Magnier/Veillet)
      1. Second skyprobe
      2. DIMM
      3. Mauna Kea weather services
    1. CFHTLS report (Mellier)
    2. Terapix report (Mellier)
    3. CADC report (Simard – written report)
    4. DOG report (Cuillandre)
  5. Telescope use and scheduling (Veillet)
    1. 2003B schedule
    2. trends in instrument use
  6. 2004 User’s Meeting? (25th anniversary!) (SAC/CFHT)
    1. venue
    2. program discussion
  7. Reflection on the role of SAC (E.D./SAC)
  8. Other items

    CFHT and external reports on the above topics were made available to SAC members through a protected CFHT web site in advance of the meeting. Authors of reports are noted below, but except where noted all reports were presented by C. Veillet.

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1) Welcome new E.D. (SAC)

SAC was pleased to welcome Dr. Christian Veillet to the SAC meeting in his new role as CFHT Executive Director.

2. Technical activities report including DEC oscillations and GRIF concerns (Salmon)

C. Veillet presented the CFHT technical activities report prepared by D. Salmon. A number of changes to the technical, scientific, and operations staff were noted. No changes were made to the current project priorities. As a result, a solution of the DEC oscillation problem remains a priority and SAC is encouraged by the full-time assignment of an engineer with extensive servo experience to this issue. CFHT now appears to be on a path to a full resolution of this long-standing problem.

SAC expressed concern with the level of CFHT staff effort devoted to recurrent problems with the GRIF focal plane wheel. This in turn led to the following recommendation:

SAC recommendation 1:

SAC recommends that if the scheduled 2003B GRIF runs can be carried out reasonably successfully without control of the focal plane wheel, then defective GRIF hardware should NOT be returned to the Observatoire de Paris until after these runs have been completed. In the meantime, Observatoire de Paris work on a revised design for the focal plane wheel should proceed immediately, with CFHT staff actively participating in design reviews. The focal plane wheel should then be shipped to the Observatoire de Paris immediately after the end of the 2003B observing runs. Since the status of the filter plane wheel repair will almost certainly not be known before the 2004A call for proposals, GRIF should NOT be offered to observers for semester 2004A. SAC also requests that CFHT report on the status of the focal plane wheel redesign by the 2003 November SAC meeting at the latest.

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SAC and CFHT staff discussed the current status of the CFH12K camera. With MegaPrime now operational the CFH12K camera will be decommissioned at the end of 2003A. Since CFHT currently have no active plans for its future SAC recommends the following:

SAC recommendation 2:

SAC recommends that CFHT investigate the possible sale of the CFH12K camera, either for cash and/or for access to telescope time on other facilities.

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3) Instrument and Project reports

a) MegaPrime status and commissioning activities     (Veillet)

Veillet presented a summary of the extensive commissioning activities for the MegaPrime project and reviewed the status of the instrument. SAC congratulates CFHT staff on the tremendous success of MegaPrime commissioning, and acknowledges the huge effort expended by a substantial fraction of the staff during this phase.
Despite these successes, given concern over the recent failure of some of MegaPrime’s electronics that has temporarily resulted in the loss of half of the field of view, SAC makes the following recommendation:

SAC recommendation 3:

In order to reduce the impact of the failure of a critical MegaPrime hardware component, SAC recommends that CFHT identify these critical components and maintain a supply of spares.

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i. Instrument status (Salmon)

Veillet presented a summary of the current status and schedule of the WIRCAM project. Preliminary tests of the dark current, quantum efficiency, and read noise of an engineering device are very encouraging. Of more concern is the large number of hot pixels, even at low operating temperatures. The ASICs development is late with regard to the previous schedule, and SAC and CFHT note that the current 2004 August date for on-sky tests may be optimistic.
If the current aggressive schedule for WIRCAM development is to be met, SAC reminds the Board of Directors that firm commitments from LAE and LAOG to make WIRCAM development a priority are required.

ii. SG report, surveys, filter selection (Beuzit)

J.-L. Beuzit presented a summary of WIRCAM Steering Group activities since the last SAC meeting. In particular, the WSG met for a 2-day meeting in Toronto in late February 2003. Detailed discussions took place about possible mechanisms to select and review WIRCAM survey programs, and to implement them at CFHT. The SAC and the SG agree that input from the member communities indicate that large and/or long-term WIRCAM projects with broad community appeal exist. Both also agree that the national TAC’s should have strong voices in the selection of these projects. SAC discussed at some length the amount of time that should be considered for WIRCAM survey projects. Given the fact that other new bright time instrumentation will be arriving on the telescope at about the same time as WIRCAM (i.e. ESPaDOnS and then possibly PUEO NUI) SAC prefers a relatively modest allocation of nights for WIRCAM survey programs to start in order to provide time to evaluate the level of demand for other bright time science, whether it be PI programs with WIRCAM or other bright time instruments. SAC therefore makes the following recommendation:

SAC recommendation 4:

SAC recommends that a more detailed, scheduled mechanism to identify and review large and/or long-term WIRCAM projects be developed by the SG with input and approval from the SAC. A very first step is to have a call for detailed WIRCAM survey proposals prepared by the WSG during the summer and sent to the communities by the beginning of September, with a deadline for receipt of proposals of mid-October. Scientific evaluation by the national TAC’s will then be crucial to define the number of nights possibly allocated for WIRCAM surveys.

With the agreement of the national TAC’s, WIRCAM large projects might be supported over a significant fraction of the bright time allocated to WIRCAM (30% as a starting point), possibly extending over several years. A recommendation based on the evaluation of this first round of survey proposals will be prepared at the next SAC meeting and presented to the Board by the end of the year. If the national TAC’s and SAC deem that no proposals in the first call for WIRCAM survey proposals are satisfactory a second call for WIRCAM survey proposals may be announced in early 2004.

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The selection of filters was also discussed by the WIRCAM Steering Group. In the present instrumental design, 8 positions are available for filters. Selected WIRCAM broad-band filters include Y, J, H, and Ks. The H and Ks filters have already been delivered but the J filter did not meet specifications. Discussion of the narrow band filter selection continues, with H2, Br?, CO(2-0) and K continuum being possible candidates, but there is clearly community interest in many other somewhat more specialized filters. However, CFHT staff caution that operations of WIRCAM is likely to be significantly different from that of CFHTIR and the Redeye cameras in that the WIRCAM dewar is likely to be recycled only once or, at most, twice per year. There will, therefore, be limited opportunity to make filter changes to accommodate highly specialized filters. Since potential WIRCAM users may not be aware of this difference in operations SAC recommends the following:

SAC recommendation 5:

SAC recommends that CFHT and the WIRCAM Steering Group quickly decide on an operations plan for WIRCAM. For example, is one dewar cycling/year the maximum number anticipated? This decision, and the budget for filters, clearly has an impact on the final decision on the narrow band filter selection.
Potential WIRCAM users are likely not currently aware of possible differences in the operation of WIRCAM vs. KIR and Redeye. SAC therefore requests that the SG ensure that the community is made aware of the limited possibility for filter changes and make the current SG recommendation for filters public to encourage a final round of discussion. Based on this discussion, the choice of filters must be finalized by 2003 September 1 and should be arrived at on the basis of scientific arguments and prospects for the optimal use of WIRCAM on the telescope.

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c) ESPaDOnS: Project status, schedule, commissioning     (Donati)

J.-F. Donati presented a summary of the status of ESPaDOnS and provided SAC with a tour of the instrument in the lab. Communication between the ESPaDOnS team and CFHT appears to be excellent and the project is proceeding very well with engineering time scheduled late in semester 2003B. The current schedule has the instrument available on a shared-risk basis in the second half of semester 2004A. Arguments for dedicating the EEV1 detector to ESPaDOnS, constructing a thermal enclosure for the spectrograph, and providing a backup detector were also presented. SAC does not support the proposal for a backup detector. There are also questions about the necessity for the thermal enclosure, given the thermal characteristics of the CFHT 3rd floor coude room provided by CFHT as part of the technical activities report and the recent published demonstration of quite routine 20 m/s velocity precision possible with Gecko and no special thermal control. SAC members were also concerned about the decision to eliminate the use of micro-Fabry lenses originally designed to be located in front of the ESPaDOnS input fibers. This will result in significant loss of science capabilities of the instrument since accurate measurements of continuum polarization will not be possible because of variations in the intensity of light entering the two fibers caused by image motion.

The following ESPaDOnS-related recommendations are therefore made:

SAC recommendation 6:

SAC recognizes the argument for the use of EEV1 as the detector of choice for ESPaDOnS. However, SAC does not want to exclude the use of EEV1 with Gecko when the scheduling of the two instruments permits. SAC notes that Gecko is unlikely to be scheduled more than once per semester once ESPaDOnS is available so that the impact on ESPaDOnS operation is not expected to be large. CFHT and the ESPaDOnS team are asked to revisit this issue.

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SAC recommendation 7:

SAC recommends that the ESPaDOnS team continue with a design for an ESPaDOnS thermal enclosure, including a cost estimate. At this time SAC is not willing to make a commitment to this possible upgrade of ESPaDOnS until upcoming engineering and commissioning tests can provide solid evidence to support the need for such an enclosure.

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SAC recommendation 8:

SAC urges the builders of ESPaDOnS to evaluate the cost, time, and resources required to provide micro lenses in front of the instrument’s input fibers, either before instrument commissioning or as a subsequent upgrade. Such micro lenses would prevent image motion at the entrance of the fibers and would greatly improve the scientific usefulness and demand for the instrument.

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d) Pueo Nui: instrument status and workshop summary     (Lai/Cuillandre)

In response to a SAC recommendation from the 2002 November SAC meeting, a Pueo Nui Workshop was held in Grenoble on 22/23 May 2003. Approximately 30 astronomers from the member communities, including 5 members of SAC, attended the workshop. Further discussions of the workshop, the Fly Eyes experiment, and CFHT staff involvement in the proposed Pueo upgrade led to the following recommendation:

SAC recommendation 9:

Given the scientific and engineering interest presented at the Pueo Nui Workshop, as well as a desire to maintain the current high level of CFHT technical expertise, SAC recommends that CFHT proceed with a more detailed study for Pueo Nui for presentation at the next SAC meeting. This should include a discussion of technical feasibility, realistic performance estimates, cost, contributions by member agencies, and a schedule. A very aggressive development schedule would increase the scientific and technical value of Pueo Nui. Outside help from the CFHT communities could facilitate this development given the current level of CFHT commitments to MegaPrime, WIRCAM, ESPaDOnS, etc.

As part of the above study, SAC also recommends that CFHT continue with the Fly Eyes experiment

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e) ‘Ohana: status, operations model, sensitivity limits (Lai)

A progress report for ‘Ohana was presented. Phase I tests at Keck in 2002 December were very encouraging with a maximum injection of 11% achieved at K. Discussions for phase II plans continue between Keck and Paris Observatory. An MOU between CFHT, Paris Observatory, and Gemini for phase I and phase II tests of the Gemini/CFHT baseline is currently under review.

f) CFHT environmental data: second skyprobe, DIMM    (Magnier/Veillet)

See CFHTLS/DOG report below.


a) CFHTLS report (Mellier)

Y. Mellier, the chair of the CFHTLS Steering Group (replacing Veillet), presented SAC with the CFHTLS Steering Group report. This included a discussion of the final survey field selection, the allocations of time to the various survey components in semester 2003A, first data release science goals and content, and a QSO scheduling algorithm proposed for inter-CFHTLS observations to ensure an equitable share of survey time among the three CFHTLS survey components. One concern of the SG and SAC is the perceived poor communication between the SG and the CFHTLS communities. This led to the following recommendation:

SAC recommendation 10:

SAC urges an improvement in communication between the CFHTLS Steering Group and member communities. As an example, SAC recommends that science goals and first data release of CFHTLS products be discussed within the communities, not just within the SG. The CFHTLS web pages should also be frequently updated.

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b) Terapix report (Mellier)

Mellier presented a detailed review of the Terapix project as well as a progress report (available at L. Domisse also provided a live demonstration of the Terapix processing pipeline, accessible to MegaPrime users from the WWW.

c) CADC report (Simard – written report)

SAC reviewed the CADC report provided by L. Simard. Of particular note are the imminent upgrade of the network link at HIA to 1 Gbit/second, and the anticipated processing of archival CFH12K camera data for subsequent distribution to archive users. First release of CFHTLS data through the CADC web pages occurred during the SAC meeting.

d) DOG report (Cuillandre)

J.-C. Cuillandre presented a report on FLIPS2/Elixir processing of MegaPrime data and provided a summary of the instrument’s bias, and bad pixel characteristics, examples of flat field images and fringing (6% at i’, 15% at z’), and the quality of astrometry and calibration being achieved during commissioning. Efforts to paint or otherwise reduce the contribution of various telescope structures (cable wraps, mirror covers, etc.) to high levels of scattered light observed during MegaPrime commissioning were also described. These efforts will continue through the scheduled August shutdown.

Reports on SkyProbe and the DIMM were also provided. It is hoped that the DIMM will be installed in the fall if other high-priority tasks permit.

SAC congratulates CFHT staff on the excellent progress made on the DIMM installation since the last SAC meeting.

5) Telescope use and scheduling (Veillet)

Veillet presented a report on telescope use, scheduling, and QSO. Of particular note is the fact that only MegaPrime is scheduled during dark time in semester 2003B. Queue operations achieved a remarkable level of efficiency in semester 2002B, with all but one A and B program completed and many C programs started. SAC is very impressed with this level of completion achieved by QSO.

Some time was spent discussing the issue of duplicate observations requested through QSO. This has occurred in semester 2003B and will no doubt occur again. An immediate solution was not developed which led SAC to make the following recommendation:

SAC recommendation 11:

SAC recommends that CFHT provide an outline of a possible solution to the issue of duplicate observations in QSO for the next SAC meeting.

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6) 2004 User’s Meeting (SAC/CFHT)

Since the last CFHT User’s Meeting was held in Lyon, France in May 2001, SAC notes that the next User’s Meeting should be held in Canada in the spring of 2004. This will also represent the 25th anniversary of the CFHT. As a result SAC makes the following recommendation:

SAC recommendation 12:

SAC recommends that a CFHT User’s Meeting be held in Canada in May 2004, likely in or near Victoria, BC.

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The meeting will be 2-3 days in duration. For example, for a 3-day meeting one day might be devoted to CFHTLS science, 0.5 day to new CFHT capabilities (WIRCAM/ESPaDOnS/Pueo Nui), 0.5 day to other science, 0.5 day to 25th anniversary reviews, and 0.5 day to CFHT replacement discussions.

Halifax is an alternative venue, but the last Canadian User’s Meeting was held in Quebec City (1998), which suggests that a western Canada venue is timely. Two of the current Canadian SAC members are also available in Victoria to take on LOC duties while the Halifax representative will be on sabbatical in Hilo in 2004.

To ensure maximum participation by the member communities SAC would prefer to circulate a First Announcement for the meeting in the fall of 2003. Therefore, with BoD approval, SAC will decide upon a venue and develop a preliminary program by mid-September 2003, with the hope of circulating a First Announcement to the CFHT communities shortly thereafter. A more complete program with invited speakers will be presented at the next SAC meeting.

A SAC meeting is expected to take place immediately after the User’s Meeting.

7) Reflection on the role of SAC (E.D./SAC)

C. Veillet reminded SAC of their role within CFHT. Copies of the CFHT bylaws relevant to the mandate of SAC were given to the committee members. He also reminded SAC members that communication by SAC with their member communities is of critical importance.

8) Other items

a) Visiting scientists

The role of visiting astronomers at CFHT was also discussed. There is agreement among SAC and CFHT staff that, along with their own research, all such visitors should expect to carry out a level of duty work for CFHT comparable to that of a resident astronomer while they make use of the Observatory’s facilities. SAC noted that it is unfortunate that there is little possibility of long-term visits by Canadian astronomers.

b) The next SAC meeting will take place in Waimea on 14-15 November 2003, with a summit visit on 13 November.

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