85th meeting of the Canada-France-Hawaii Telescope

Scientific Advisory Council

Strasbourg, France, May 27-28, 2014

Note: The report presented below is the public version of the SAC report as amended by the CFHT Board of Directors in accordance with the CFHT Communications Policy.

After deliberation at a special Board Meeting teleconference call convened on 24 July 2014, the CFHT Board of Directors, in consultation with the Executive Director, endorsed SAC’s recommendations.

Recommendation 1 MOS/OSIS, Gecko/CAFE, CFHTIR and AOB/KIR be decommissioned.
Recommendation 2 Order of work priorities
Recommendation 3 Acceptance of two new Large Programs for 2015A—2016B

Report of the 85th meeting of the CFHT Science Advisory Council, May 2014

The 85th CFHT Scientific Advisory Council meeting was held in Strasbourg, France, 2014 May 27-28. SAC members Hervé Aussel (vice-chair), Pauline Barmby, Magali Deleuil, Thierry Forveille, Andrew Howard, Rodrigo Ibata, JJ Kavelaars, Marcin Sawicki (chair) and Gregg Wade attended the meeting. Wei-Hao Wang from the Academia Sinica Institute of Astronomy and Astrophysics in Taiwan and Byeong-Gon Park from the Korea Astronomy and Space Science Institute attended the meeting as invitees. The CFHT Executive Director (ED) Doug Simons, Director of Science Operations Daniel Devost, and Director of Engineering Derrick Salmon made presentations and participated in the discussions. SAC also had a video-con Q&A with Jean-Francois Donati to discuss questions arising from the SPIRou large survey plan submitted by the SPIRou team.

1. Telescope use and scheduling report

SAC received reports on Time Allocation and Queued Service Observing (QSO). Much larger than normal amounts of observing time were lost in 2013B due to weather, particularly during the winter months at the end of the semester. The poor weather led to below average QSO completion rates in 2013B, particularly for MegaCam and WIRCam. We learned that the number of requested nights on MegaCam, WIRCam, and ESPaDOnS remained high and nearly constant from 2013A to 2013B, while demand for AOB remained low (3 accepted nights) and the instrument was not scheduled. The report on RA pressure was helpful and SAC recommends distributing this information to CFHT user communities.

2. Development status report

2.1. Dome venting

The dome venting project is reported to have gone very smoothly, impressively so. All dome vents are now installed and only minor issues associated with the shipping process required remediation. There has not been sufficient usage, yet, to determine the impact of dome venting on the image quality. During the next months CFHT will undertake the extensive monitoring and data gathering required. SAC looks forward to a report on the results of dome venting on image quality.


Due to technical problems the work on SITELLE is somewhat behind schedule. A problem with vibration of the beam splitter, apparently caused by a mechanical resonance, was resolved by ABB and the instrument is now close to reaching the original design goals for stability. Some additional testing in the blue will be needed.

CFHT is requiring that cold room testing be performed prior to acceptance. The delays caused by vibration issues resulted in loss of scheduled access to a testing facility at Laval and the team will likely need to wait until September before access is provided. This will delay shipment to CFHT.

Work at CFHT to be ready for SITELLE is proceeding apace. CFHT is renovating various areas in the dome, including the old visitors gallery, to make room for SITELLE. Various components to allow SITELLE to be integrated into the operational environment are being manufactured. The first two filters that CFHT has ordered have arrived and a third filter has been received at Laval. Additional filters will soon be ordered but the current set is sufficient for acceptance and commissioning.

SAC encourages the CFHT to continue its good work with the SITELLE team to ensure that the instrument is available for 2015A.

2.3. MegaCam upgrade

After an RFQ process new, larger MegaCam filters have been ordered. Delivery of all filters is expected in early fall 2014 and SAC looks forward to receiving a report on the commissioning of the new filters at the November 2014 meeting.

Shortage of CFHT staff has delayed starting work on improved detector readout speeds. These staffing issues are now being resolved and some effort to determine the feasibility of the readout improvements should be available by the time of the November 2014 SAC meeting. SAC looks forward to receiving a report on those activities at that time.

2.4. SPIRou

SAC was pleased to hear that SPIRou recently passed Final Design Review (FDR). Work at CFHT will proceed to prepare for SPIRou with no major issues at CFHT currently known. The SPIRou FDR committee did not provide the document that described the FDR outcome in time for a complete review at this SAC meeting. SAC does note, however, that the CFHT technical assessment encourages the SPIRou team to develop a more realistic schedule and risk assessment. SAC notes that a realistic delivery schedule will be critical when considering the scheduling of future large programs/legacy surveys, including a possible SPIRou Legacy Survey.


SAC was very pleased to hear of the successful first light for GRACES. This project provides a great possibility for science and for collaboration between CFHT and Gemini. It is now up to Gemini to proceed with the GRACES project. SAC encourages CFHT to make the required changes to ESPaDOnS that will allow the use of GRACES to be non-disruptive to CFHT operations.

3. Decommissioning of instruments

SAC received a recommendation from the CFHT staff to decommission previous-generation instruments: MOS/OSIS, Gecko/CAFE, CFHTIR and AOB/KIR. CFHTIR is 15 years old and has been supplanted by WIRCam; MOS/OSIS and Gecko/CAFE are both more than 20 years old. Only AOB/KIR is still offered to the community, although recent demand for AOB has not reached the minimum of 7 nights required for it to be scheduled and the instrument was last on the telescope in 2012B. Because the hardware and software for all of these instruments are old and corporate memory of how to troubleshoot them is fading, putting any of them on the telescope would be risky in terms of the actual science gain compared to the resources required. While a working AOB/KIR might be slightly more efficient for bright targets compared to AO systems on larger telescopes, the time lost to instrument problems would likely outweigh this gain.


SAC recommends that MOS/OSIS, Gecko/CAFE, CFHTIR and AOB/KIR be decommissioned.

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4. Operational and development priorities:

SAC noted that many exoplanets proposals rely on the ability of WIRCam to deliver repeatable mmag precision measurements, and is concerned that such accuracy could not be delivered due to some instrumental instabilities in the thermal control, filter changes and instabilities. SAC therefore requested that the characterization of WIRCam nonlinearities be added to the list of pending work.


SAC recommends the following order of work priorities:

    1.    Normal operations
    2.    Dome venting characterization
    3.    SITELLE comissioning
    4.    MegaCam new filter commissioning
    5.    TCS upgrade
    6.    MegaCam readout controller
    7.    WIRCam nonlinearity characterization
    8.    OPERA for ESPaDOnS
    9.    WIRCam data pipeline
    10.    Dome shutter work

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5. Large Programs

5.1. Ongoing Large Programs

SAC reviewed the status reports from the BinaMIcS, MATLAS, MaTYSSE, and OSSOS Large Programs, and was satisfied with their progress given the adverse weather over the last two semesters. SAC worries, as the MATLAS investigators do, that the outcome of MATLAS could potentially be significantly degraded by its 2013 weather losses (although CFHT staff are confident that the project could be successfully completed given good weather during the coming semesters).

5.2. New Large Programs for 2015—2016

SAC reviewed the report of the Large Program Ad-Hoc Review Committee (LPARC) on the four submitted proposals for new Large Programs in the 2015A—2016B (inclusive) semesters. The LPARC consisted of four members from Canada and three from France appointed by the CFHT ED. SAC thanks the LPARC members for their dedicated work in reviewing and ranking the proposals.


After review of the LPARC report, national TAC feedback, and the proposals and technical reports, SAC recommends the acceptance of two new Large Programs for 2015A—2016B:

  1. CFHT-Luau (McConnachie et al.) with a reduced allocation of 350 hrs, with a 200 hr / 150 hr split between the Canadian and French agencies, respectively (as described in detail further below).
  2. HMS (Petit et al.) with the full requested allocation of 215.8 hrs.
SAC recommends that the allocation of CFHT-Luau be of 50 hrs of Canadian time in semester 2015A to allow for MATLAS to be completed and still leave enough room for PI programs. This is to be followed in the subsequent three semesters with 100 hrs per semester consisting of 50 hrs of Canadian and 50 hrs of French time.

Should conflicts arise between LPs competing for the same time, priority should be given to completing ongoing LPs (OSSOS, MATLAS, BinaMIcS, MaTYSSE) before starting new observations.

Both new LP allocations should obey the same guidelines (Recommendations 9 and 10 of the May 2008 SAC report) as the four LPs from the last round, incompletely repeated here as: (1) submit to CFHT by early February and early August of each year an estimate of their expected RA pressure and observing conditions for the following semester, which will appear in the call for proposals, and (2) submit to both national TACs (two weeks before their meetings) and SAC a short outline summarizing the status of the data acquisition, processing, and analysis.

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6. Future very large programs planning

In its September 2013 meeting report SAC stated that CFHT should consider very large surveys as a possible route to maximizing the scientific impact of the new/upgraded CFHT instruments. Such surveys, if they go ahead, would likely start in 2017A and with this in mind SAC has started discussing possible mechanisms for initiating such surveys. A summary of current discussions follows, with the caveat that we will further develop ideas over the next months and will likely prepare a SAC Recommendation on the issue in our November 2014 meeting.

Some of the possibilities for initiating very large programs that SAC discussed include:

  • multiple independent fully-developed proposals competing for the full available time or portion thereof in the spirit of the current calls for Large Programs

  • white papers expressing survey ideas leading to a merged survey plan down the road in a fashion similar to that used for CFHTLS

  • a single fully-developed proposal submitted by the community.

Various other aspects were also discussed, including:

  • lessons learned from the CFHTLS

  • proposals should include: science case, technical justification, and - very importantly - a full and realistic management plan

SAC notes that the full exploration of these issues will take more time than was available at the present meeting and also that the issue is not yet pressing. SAC welcomes input from the community on the possible format for the decision process and format of the surveys. SAC will discuss the issue in more depth at its 2014B meeting in Waimea.

7. SPIRou survey proposal

SAC received an unsolicited document describing an ambitious multicomponent survey to be carried out with the SPIRou IR spectropolarimeter. This SPIRou Legacy Survey (SLS) is estimated to require approximately 500 nights, with 300 nights for a sensitive RV search for planets around nearby M dwarfs, 75 nights for follow-up of transiting planets discovered by future photometric surveys, and 125 nights for monitoring of protostars and their accretion discs. During its face-to-face meeting, SAC met by Skype with the SLS PI, J.-F. Donati, who provided helpful input and clarification regarding the proposal.

The SLS proposal was reviewed in the context of the extensive discussion by SAC of post-2016B LS/LP strategies for CFHT. Although a decision has not yet been reached, SAC generally agreed that an open approach to LS/LP allocation with broad community involvement is obligatory.

We commend the SPIRou team for being pro-active in starting to develop a survey plan to maximize the scientific return of this unique instrument. We encourage the team to keep developing their plans and also to build their team further to include as many interested community members as possible.

8. Next SAC Meeting

2014 November 16-17-18 in Waimea