Report of the 77th meeting
of the Canada-France-Hawaii Telescope
Scientific Advisory Council

10, 11 May 2010 - Vancouver, British Columbia, Canada

NOTE: The report presented below is the public version of the SAC report as amended by the CFHT Board of Directors.

After deliberation, the CFHT Board of Directors has endorsed SAC’s recommendations No. 3 – SPIRou draft science case document, and No. 4 – 'Imaka phase A proposal.

The remaining recommendations will be further discussed at the Board's next regular meeting, December 2010.


Recommendation 1: CFHTLS T0007 release
Recommendation 2: Large Programs Mid-term review
Recommendation 3: SPIRou Draft science case document
Recommendation 4: 'Imaka phase A proposal
Recommendation 5: Declination pointing investigation


The 77th CFHT SAC meeting was held at the University of British Columbia in Vancouver Canada May 10-11/2010, hosted by the Department of Physics and Astronomy. SAC members John Blakeslee, Mark Chun, Thierry Contini, Pierre-Alain Duc, Brett Gladman (chair), Denis Mourard (vice-chair), David Sanders, Gregg Wade and Jon Willis attended the meeting. SAC member Coralie Neiner did not attend (although participated in the CFHT-TAC meeting on the second day via telecon). Yoichi Oyama, from the Academia Sinica Institute of Astronomy and Astrophysics in Taiwan, attended the meeting as an invitee. The CFHT director Christian Veillet, Derrick Salmon, and Daniel Devost participated in presentations and discussions.

0. Board feedback to SAC

The 1996 communications policy was discussed, and it was agreed that future SAC meetings would begin with a brief oral review by the Executive Director of the previous SAC report, providing commentary if needed from the perspective of Board's deliberations.


CFHTLS is one of CFHT's major scientific successes. The 2010 users' meeting will provide another opportunity to present its scientific achievements and potential for future exploitation by the worldwide community. This will be vastly improved by the announcement of the next CFHTLS releases.

Recommendation 1: CFHTLS T0007 release

SAC recommends all efforts be made to have the CFHTLS T0007 release occur before the November 2010 CFHT Users meeting.

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2. LP progress reports

SAC felt the progress reports from the four currently operating large programs indicate all have been proceeding satisfactorily in 2010A. A request from MaPP to move time from 2012B to 2010B was accommodated by the Mimes collaboration volunteering to move time out of 2010B. The original LP call stipulates a mid-term review which SAC judges should be submitted by all four of the original LPs. As per the original implementation procedure, these should include: (1) progress report (data acquired, publications, etc), (2) an update on the observing plan for the remainder of the LP, (3) any significant change in co-I status and other LP participants that could alter the agency balance. In case of an unsatisfactory review, the allocated time may be modified. Programs may request up to 5% increases in their allocation for highly successful programs if this increase will provide a meaningful targeted scientific return and/or enhance the legacy value of the LP.

Recommendation 2: Large Programs; Mid-term review

The Pandas, NGVS, MAPP, and Mimes LPs provide SAC (with an informational copy to the national agency TACs) with a mid-term review by October 15 2010.

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3. New Large Programs

SAC reviewed the Large Program Ad-Hoc review committee (LPARC) report on the 6 submitted proposals for new Large Programs in the 2010B-2012B (inclusive) semesters. The LPARC consisted of three members from each of the C and F agencies, appointed by those agencies. After review of the LPARC report and the science case proposals, SAC recommended to the CFHT Executive Director to accept the two programs with the highest LPARC ranking: 1. Thermal Emission of Transiting ExoPlanets (TETrEs). Jayawardhana et al 2. Searching z~7 quasars with WIRCam in the CFHT-LS Wide fields. Cuby/Willot et al. Both of these proposals use WIRCam and the ranking above is that which CFHT should respect if conflicts arise. Both of the above proposals should obey the same guidelines (Recommendations 9 and 10 of the May 2008 SAC report) as the first four LPs, 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. A longer (Mid-Term) review for these two LPs should be submitted for the November 2011 SAC meeting. SAC does not see an opportunity for another call for LPs until 2012 (for observing time beginning 2013A). With the two new LPs, the fraction of time allocated to LPs in the 2010B to 2012B period ranges from 29 to 43 percent (depending on the semester), with 36% as an average.

4. SPIRou

SAC received a draft science case document in response to Recommendation 6 of the Nov 2009 SAC report: "SAC recommends that documents clearly describing the science drivers of SPIrou and alternate IR spectro(polari)meters be ready for the SAC meeting to be held in Spring 2010. A comparative study summary sheet of the various IR spectro(polari)meter options should be presented to SAC which make it clear which science cases require which capabilities." The document did not contain a summary sheet, although Section 8 of the Spirou report contained statements regarding the requirements; SAC member Gregg Wade assembled a draft summary table from the report which SAC reviewed.

Recommendation 3: SPIRou Draft science case document

SAC strongly recommends that the SPIRou team continue to improve the Scientific Rationale for the instrument before the Phase A submission, in a strong iterative process that involves its science team. The science-team contributors for each sub-section of the science case should be identified. The team should fully address all scientific objectives, in particular providing estimates of observing strategies and time required for all the science cases, with justification of the sample sizes. The team should provide a concise tabulation of the relationship between each of the technical requirements of the instrument and the science objectives, as originally requested in the December 2008 Board resolution. An example of such a tabulation, as developed by SAC, will be communicated to the Spirou PI by end of May 2010. The team should be prepared to clearly justify any differences between their own tabulation and that developed by SAC, as part of their Phase A submission due Oct 1 2010.

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5. `Imaka

SAC was impressed with the quality of the feasibility study report, which in many aspects is much more advanced than a strict feasibility study. It is important that a Phase A study would need to provide a detailed system analysis which integrates, in a global model, all the technical aspects worked out in this feasibility study. This system analysis should address the interface with the CFHT telescope. The document provides a broad variety of science cases. As this is normal for the kind of general facility provided by the 'IMAKA instrument, the proposal would be greatly improved if the image-quality dependent science cases are supported by a quantitative discussion of how the expected scientific return depends upon incremental image quality improvements for optimal, nominal or degraded conditions. These highlighted science cases should be clearly described in terms of number of nights, survey strategy and other observing parameters. SAC considers some of these science cases as clearly compelling and urges the team to reinforce the science document with a more focussed presentation. CFHT and SAC requested external reviews of the technical aspects of the feasibility study. SAC feels these reports provide substantial independent confidence that the instrument is technically feasible. SAC considers it important that the team present a phase A plan that shows how the Phase A study would address detailed issues such as: - The assumptions on the spatial and temporal properties of the AO DM and of the wave front sensors have to be consolidated by the continuation of the turbulence measurements. Indeed, the bandwidth errors of the correcting devices have to be considered and consistent with the turbulence characteristics. - The team has ignored the contribution of the dome venting for the feasibility study, which is pessimistic. For the phase A they should be careful to outline how the now-approved dome venting (and assumptions on its effectiveness) impacts the performance and system requirements. - The team should develop a complete error budget for the image quality. This should include the impact of dome venting. - The simulations of the GLAO and OTCCD performances should clarify how the percentage of time for the optimal image quality is affected by the field characteristics and by the external observing conditions: local and free atmosphere seeing (already done), position and number of guide stars (GLAO and OTCCD). - Finally it appears that it would be necessary to develop a model of the 'IMAKA PSF over the large FOV to reach the full performances on astrometry and photometry. This should correctly take into account all the subsystems of the instrument. An aggressive schedule is presented. It should be consolidated by the clear identification of the resources needed for the phase A step and during the phase A for the following phases of the project.

Recommendation 4: 'Imaka phase A proposal

SAC encourages the 'IMAKA team to develop a full phase A proposal for this fall. Documents should be received before October 1/2010.

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6. Gyes

SAC received information on the progress of an externally-funded study for the GYES instrument, submitted via the CFHT director. SAC did not request a document for May 2010; lacking access to this information before the SAC meeting, SAC spent only a small amount of time considering this progress report. SAC repeats its willingness (stated in the November 2009 SAC meeting) to review a full phase A proposal if submitted by October 1/2010. The phase A study should build upon the feasibility study by providing a detailed science case where instrument performance is justified by science requirements, and will receive an external review. In addition to the technical and scientific case for the instrument concept, the phase A proposal should also identify specific individuals and labs responsible for specific areas of the system and the project management for the instrument, along with realistic time tables. The issue of the manpower resources that would be required to exploit the scientific data from Gyes (once on the sky) at the same time that the community is dealing with the Gaia data must be discussed. The study should also demonstrate cross-community support for the instrument concept and science case; if not, SAC would likely request a clear statement from the French agency as to how they would view Gyes time allocations as a single-agency instrument (possibly in direct competition with Spirou).

7. Technical Activities report

SAC reviewed the technical activities report delivered by Derrick Salmon. The last 6 months have been relatively smooth from this point of view. The operational priorities need not change. SAC is pleased that dome venting is proceeding, and still hopes that the dome work could begin in summer 2012 in order to reach operational status by 2013A. The Declination pointing issue is still on the table, and SAC was concerned to hear that the amplitude of the variation was increasing linearly with time. The work has revealed a systematic pattern in the declination error which appears predictable and could thus be incorporated into the pointing model (which should reduce some overheads currently occurring in Espadons operations, even though this will have no effect on the underlying problem).

Recommendation 5: Declination pointing investigation

SAC strongly recommends that CFHT continue its vigorous investigation into the Declination pointing problem. If CFHT feels it is suitable, SAC recommends incorporating the current systematics into the pointing model as a temporary measure to improve operational efficiency.

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8. 2010 CFHT User's meeting

The 2010 CFHT User's Meeting will occur in Taiwan November 16-18 2010. The Scientific Organizing Committee has been formed and SAC began planning the UM highlights.

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