90th meeting of the Canada-France-Hawaii Telescope

Scientific Advisory Council

Waimea, 16-17 November, 2016

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 during its December 2016 meeting, the CFHT Board of Directors, in consultation with the Executive Director, took note of the following SAC's recommendations:

Recommendation 1 MSTAR Project
Recommendation 2 Time Allocation Committees meeting scheduling
Recommendation 3 Availability of bright and dark time to PIs
Recommendation 4 Gemini time exchange clarification
Recommendation 5 MegaCam Upgrades: Fast Readout Mode
Recommendation 6 Large Program web pages
Recommendation 7 Operational and development priorities

Report of the 90th meeting of the CFHT Scientific Advisory Council,
November 2016

The 90th CFHT Scientific Advisory Council meeting was held in Waimea on November 16-17, 2016. SAC members Hervé Aussel (chair), Stéphane Courteau, Magali Deleuil, Tristan Guillot, JJ Kavelaars (vice-chair), Nicolas Martin, Roberto Mendez, Kim Venn, Richard Wainscoat and Chris Willott attended the meeting. The CFHT Executive Director Doug Simons, the CFHT Director of Science Operations Daniel Devost, the CFHT Director of engineering Derrick Salmon, CFHT Optical Engineer Gregory Barrick and CFHT Software Manager Kanoa Withington participated in presentations and discussions, together with numerous observatory staff who provided very useful information to fuel the discussions.

SAC commends all CFHT staff for successfully operating a great instrument suite and developing exciting new capabilities.

SAC heard an update from the CFHT executive director about the evolution of the political landscape for future development at the summit of Maunakea. SAC was pleased to see that astronomy is regaining some support in the community, thanks in part to the outreach and education initiatives put in place by CFHT staff. SAC thanks again the CFHT Executive Director and its staff for their repeated efforts to engage the communities in Hawaii in shaping with CFHT a common future.

SAC heard from executive director of a long term plan named “MSTAR” pursued by UH, EAO, Imiloa Astronomy Center and CFHT to jointly operate SPIRou at UKIRT, in conjunction with a large educational program, after execution of the LP at CFHT. SAC is supportive of this idea that should be further studied with the SPIRou Team in order to ensure a proper cross-calibration between SPIRou@CFHT and SPIRou@UKIRT.

RECOMMENDATION 1: SAC recommends to continue to explore the MSTAR project.

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Telescope Use and Scheduling Report

SAC received a report on the usage of telescope time in 2016A/B. Expectations for 2017A could not be reported as the French TAC had not yet met. The ITAC will meet via teleconf when the FTAC rankings are available. The delay also affects the Gemini-CFHT exchange program. The ITAC will likely be held after December 6. The delay in the ITAC has repercussions such as delay of Phase 2 release to PIs, and compression of time for PIs to complete their Phase 2 programs.

RECOMMENDATION 2: The SAC recommends that all Time Allocation Committees meet early enough so that programs can be transmitted to CFHT by May 1 for semester B or November 1 for semester A.

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At the request of the SAC, the CFHT has provided a more detailed breakdown of instrument pressure by science area together with the classical agency breakup. SAC notes there is still strong demand from a broad range of science areas for all instruments. The time request in 16A was imbalanced between dark and bright time, resulting in a poor completion of highly ranked dark time programs and a good completion of lowly ranked bright time programs. Given that from 17A onward, there is more bright time available to PIs than dark time due to the LP scheduling.

RECOMMENDATION 3: SAC recommends that:

  • TACs be informed of the amount of time available to PIs in bright and dark time before all respective TAC meetings take place.
  • TACs rank ordered list appropriately matches this amount of bright and dark time available.

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The SAC also noted that no Canadian Time Allocation Committee member is on SAC, and is concerned that this limits their ability to advise on ITAC issues.

In 17A, the Gemini-CFHT exchange related to GRACES allows to offer 7 nights on Gemini. SAC is concerned that the availability of this observing time was not advertised enough (including not being announced as part of the CFHT call for proposals). Furthermore, the method used produced multiple paths to apply for Gemini observations for both the C and H communities that were not well understood. It was unclear for the users whether the Gemini time available through this process was all on Gemini North, or was spread across both telescopes, and whether the Gemini time was to be observed as a mini-queue or a regular queue.

RECOMMENDATION 4: SAC recommends that the proces for the Gemini exchange be clarified. In particular:

  • CFHT clarify the split of payback time in the Gemini-CFHT exchange program with respect to Gemini North and South
  • CFHT to pursue folding the CFHT-GEMINI exchange time into the regular Queue operations to help provide a cleaner process for ranking, scheduling and execution of these programs.
  • CFHT to advertise the availability of the program together with its own call for proposal on the same webpage.

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Development Status Report


There has been significant progress on SITELLE since the last SAC meeting in May. Several science runs, some engineering runs and many improvements on observing, calibration and data reduction processes. The Modulation Efficiency issue has been largely resolved with mirror tilt-control changes. The IQ problem remains to be solved despite considerable effort by CFHT staff to identify the cause.

Transfer of knowledge from the instrument team to the observatory has been good and is ongoing. The data reduction pipeline is now being run at CFHT and processed data will shortly be available through the CADC. Several papers have been submitted and SAC is impressed by some of the promising results obtained. CFHT looks well positioned to continue supporting SITELLE for users’ science projects.

Megacam Upgrades:

CFHT presented to SAC the outcome of their investigation to improve the readout speed of the camera. SAC was pleased to learn that the readout time could be shortened by 6.9 seconds from 40.8 sec to 33.9 sec with minimal impact on the image quality. Observations with blue (u', CaHK) or narrow-band filters suffer from a slight noticeable increase of a few ADU counts for ~200 columns on the edge of the CCD. Tests performed by CFHT show that this slight increase in counts affects neither point-source photometry, nor LSB-type observations. Solutions have been presented to mitigate their impact on the images.

For this speedup to be effective, all other actions between the end of an exposure and the beginning of the next need to take place faster than the readout time. A quick investigation during the meeting showed that this is not always the case.

RECOMMENDATION 5: Given the positive outcome of the tests presented above, SAC recommends that Megacam be operated from 17A onward in the fast readout mode. The SAC further recommends that CFHT investigate the on-sky overheads experienced by MegaCam and determine what the actual overheads are. This is critically important to ensuring that the efficiencies gained by accelerating the readout can be realized as on-sky performance improvements.

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CFHT noticed an improvement on the photometric u band data after mirror aluminization. Whether these aluminizations should be done more frequently (currently every three years) remains to be decided. However, a more quantitative evaluation is needed. The next aluminization will take place in the summer of 2017, hence this is not urgent but it should still be an item for discussion at the next SAC meetings.


The SAC heard a detailed presentation from the SPIRou team (the project manager and the PI and co-Pi) gave on the status of the instrument. The instrument integration has started and acceptance tests will be on going till the end of 2016. Aware of the very tight schedule and to mitigate the risk any delay in the delivery of the science grade detector could induce, the team has shown that the performance verification and the commissioning of the instrument can be done with a H2RG detector from ULaval or the UH H4RG detector. The validation plan has been revised accordingly. The verification of performance in lab will take place beginning of 2017 and should provide information on the expected on-sky performances. Shipment to CFHT is expected to take place by the end of July 2017 with final acceptance tests at CFHT Q3 2017, and on-sky technical and science commissioning end of 2017- beginning 2018. SAC acknowledges the huge work done by the teams in France, Canada and at CFHT and looks forward to a successful validation of the SPIRou instrument with the H2RG detector in the spring of 2017. SAC note that the SPIRou operation will be able to start once the science grade H4RG detector has been delivered in Q1 2018.

Operation Status and upgrades

OPERA / Libre-Esprit data pipelines:

The two amp mode is now available in Libre-Esprit. In addition, Libre-Esprit data products remain better for most modes compared with OPERA, which is assumed to be due to L-E having a better model of the instrument, such as slit tilt, and optimized extraction routines. While OPERA is open source, and is now available to the GEMINI-GRACES community, overall the quality of the data from ESPaDOnS is better with Libre-Esprit. Thus, work on the OPERA pipeline will not continue, it will be summarized in a publication, and data products from Libre-Esprit will continue to be delivered to the PIs. OPERA has been made available and it is hoped that others will continue the development and maintenance of OPERA.


SAC was informed that a vertical noise pattern in WIRCam caused by grounding problems has been identified and a software solution implemented.

CFHT also report on the substantial effort has gone into understanding the overhead costs associated with various WIRCam observing modes. CFHT reports that a substantial overhead is present in various observing modes. As a result of this increased overhead the CFHT is now charging a higher overhead cost on WDP model WIRCam observations. This charging of higher overheads for particular observing modes is consistent with the SAC’s desire to have a clearer picture of the various overheads associated with CFHT observing and a proper charging of those overheads to the programs that incur them.


Espadons/GRACES are working smoothly. A thorium calibration lamp and communications fiber were both replaced to fix minor operating errors. A checkout script was developed for GRACES to allow CFHT staff to easily check out the instrument prior to a GRACES run. The optics conduit permit requires renewal.

The SAC suggests CFHT investigate putting Espadons and SPIRou on a sliding system, so that both instruments could be used, very close in time, and/or for rapid instrument exchanges.

The CFHT/Gemini GRACES collaboration agreement will run through the end of the 2018A, and this has prevented GRACES to be offered for Large Programs at Gemini. Given the great success of the GRACES project, the SAC would like to renew this collaboration agreement for an extended time, so that GRACES could be offered in the next Gemini Large Program call.


SAC also learned of the substantial efforts that are going into improving the QSO PH2 software system, including the implementation of an API based PH2 system. The SAC encourages CFHT to continue consulting with the communities on these changes and to welcome as many early adopters of the new system as it is feasible for them to support.

Large Programs

SAC received reports from all ongoing LPs. All LPs are on track to reach a satisfactory completion level at the end of semester 16B, and all are producing good results.

SAC discussed the possibilities to enhance and secure the impact of Large Program data sets. It was noted that the amount of information available from CFHT web pages is not homogenous, and that links to the datasets are not provided.

RECOMMENDATION 6: SAC recommends that each LP provide CFHT with the following content to make a web page per LP on CFHT web site:

  • abstract
  • list of main papers
  • CADC query to obtain the datasets.

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Individual feedback to ongoing LPs


The OSSOS survey is nearing completion. The survey aims to characterize the population of small Kuiper Belt Objects (KBOs) and dwarf planets in the outer solar system. After a phase which required multiple observations to find these objects, the team is now able to publish the first results of the survey. The team estimates that ~900 objects will eventually be characterized, matching or exceeding expectations from the large program. Four articles have been published or are in press and one is submitted. The discovery include a dwarf planet in a 9:2 resonance with Neptune and constraints on the binarity and colors of KBOs that can potentially constrain formation processes in the outer solar system. The articles are well cited, showing that the community is starting using the OSSOS results. We look forward to the publication of the next results and to the completion of a successful program.


The BinaMicS team provided a summary of the status of the LP observations. The project is likely to receive its complete set of observations by the end of 16B. Unfortunately only 2 new Hot Magnetic Binary systems were found but the team has conducted substantial follow up of the known sample of Cold and Hot Magnetic Binaries. Some papers are being published and the team expects to publish more in the near future, in particular the SAC looks forward to the survey paper based on the nondetection of magnetic activity in the Hot Survey Component.

The BinaMicS team reports that progress on analysis and science has been slower than desired due to human resource issues. The SAC encourages the BinaMicS team to consider making available a good enhanced data archive of reduced BinaMics spectra to help ensure the maximum impact of this LP.


The MaTYSSE team provided a detailed and extended summary of the status of the LP in terms of observations and results. The scientific results are impressive on both stellar and exoplanet science. The program has allowed the detection of a hot Jupiter around a young star for the first time, followed by a second one. These challenging detections are an excellent way to show and promote the capability at CFHT. SAC is now longing forward for the others results that will come from the analysis of all the data collected during the course of the program.


SAC received an interesting report from Luau on their progress. The survey has gone well and most of the project goals will be attainable. The data quality is very good and the team has put a lot of work into calibration. We encourage the Luau team to share their calibration method and results with CFHT staff to improve MegaPrime calibration for all users. We look forward to the science enabled by the combination of Luau and Gaia data and publication of the first papers.


Observations for the HMS project have been completed for 14 out of the 18 targets of the program, and the remaining 4 targets should be completed by the end of 16B during the two remaining EsPaDoNS runs because the observing strategy being robust against occasional clouded out nights. The data analysis is progressing well, with spectrum modelling, period analysis, and magnetic modelling being completed for 10 stars. Moreover, the team has secured additional PI time to increase the scientific return of the program. The team is publishing their results, with 2 new paper published in 2016, 2 more accepted and one submitted. SAC is pleased at the progress of the survey and look forward to the publication of the magnetic properties in all the stellar age bins.

2017-2019 LPs

SAC obtained reports from all three Large Programs scheduled to start observing in 17A presenting observations plans and discussing the impact of the final allocation on the science program.


VESTIGE presented an updated plan to accommodate the lower time allocation compared to the original proposal. SAC is pleased to note that the science goals should not suffer from the smaller allocation and that the team is enthusiastic about the outcome of the program. The observing plan is solid.


SAC is pleased that the CFIS LP will proceed as planned. The matching of the Luau u-band with the PS1-recalibration of the SDSS catalog that is produced through extrapolated stars’ SEDs in collaboration with Pan-STARRS is somewhat of a concern. It remains to be demonstrated that this procedure will yield photometric accuracies consistent with expected internal and external calibration standards. The proprietary period will follow a 3-2-1 year proprietary rule, as detailed in the CFIS proposal and as originally approved by the LP TAC and SAC.


The CIPP LPs received its full requested allocation and is ready to start its observation in 2017A as planned.

Future LPs beyond 2017

SAC understands that the Board requests to have a LP Call including 300 nights with SPIRou over the three first years of operation, when the instrument is about one year from first light.

SAC believes that verification of performance from laboratory tests in advance of the LP Call is critical, so that prospective users are aware of the expected on-sky performance. This critical information is not available at the moment.

Given the tight schedule and significant schedule risk, SAC will re-assess the scheduling of a LP Call for at least 300 nights with SPIRou (and possibly more time, including all instruments) at its next meeting in May 2017. If the results of laboratory tests are as expected then SAC would issue the LP Call soon after its May 2017 meeting for a selection at the November 2017 SAC meeting, adoption by the board with a view to starting LP observations in semester 18B, with the possibility to begin during the last few months of 18A if the instrument performance meets the requirements of the LP observations.

SAC reiterates that should the Integration and Acceptance tests at IRAP be delayed beyond SAC May 2017 meeting, SAC is willing to organize a special teleconference with the team when tests are completed in order to avoid further delays until its next meeting.

Operational and development priorities

RECOMMENDATION 7: SAC recommends the following work priorities for the coming months:

    1.    Normal operations
    2.    SPIRou
    3.    Megacam fast readout
    4.    PH2 improvement
    5.    Observation efficiency improvement
    6.    SITELLE IQ improvements, modulation efficiency and operational issues
    7.    SITELLE Software
    8.    Mirror cover for IQ improvement

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Next SAC Meeting

The next meeting of the CFHT SAC will occur May 4-5 2017 in Victoria BC.