Queued Service Observations with SITELLE

Phase 1 Proposal Submission Instructions

Updated Aug 19, 2020

Table of Contents

A - Introduction

B - Important information and news

C - NorthStar

D - Applicants

E - Justifications

F - Observing Requests

G - Target list and declination limits

H - Additional issues

Z - Check list

A - Introduction [Back to Table of Content]

SITELLE and the QSO mode

SITELLE is CFHT's optical imaging Fourier transform spectrometer (IFTS). SITELLE provides integral field unit (IFU) spectroscopic capabilities in the visible (350 to 900 nm) over an 11 by 11 arcminutes field of view, with a variable spectral resolution, depending on the requirement of the observer. Observations have been carried at R up to 10,000 so far.

For details about that instrument, please see its webpage, in particular the page with information about its filters. For additional questions, please contact Laurie Rousseau-Nepton (r-nepton -=at=-

SITELLE is offered under the Queued Service Observing (QSO) mode only. The main concept behind the QSO scheme is to perform observing programs only during sky conditions or time constraints required to meet their science goals, as defined by the investigators. This can only be achieved if the programs are all grouped together in a database and are selected appropriately according to a set of constraints, rules and sky conditions. Programs are then carried out by a well trained, local team of observers in a service mode (i.e. investigators are not present at the observatory).

Before submitting a CFHT proposal, please read the short tutorial How QSO works at CFHT. [Keywords: QSO, Regular/TOO/Snapshot programs, Deadlines, NorthStar, Exposure Time Calculators, Technical Evaluations, TAC, Ranking, QSO grade, C programs, Snapshot programs, PH2, Observations, Sky conditions, Calibrations, Night Reports, Data reduction and distribution, Proprietary period, QSO rules, Contact information.]

NorthStar Phase 1 Tool

CFHT is using the NorthStar Phase 1 tool. NorthStar is used by Principal Investigators (PIs) to submit their proposal(s). All new PIs must register as new NorthStar users; the registration page offers a Help file if assistance is needed. The login information from NorthStar is NOT transferred to PH2. After login in, Help on how to use NorthStar is available on each page.

For technical information regarding SITELLE, please see the SITELLE page.

B - Important information and news [Back to Table of Content]

Please consult the generalities regarding the current Call for Proposals.

Extension of the proprietary period for metadata

PIs have the option of requesting a delay in the reporting of the metadata with appropriate justification in their proposals. This can be done via Northstar by checking "Yes" to the "Exception to the Community/World proprietary periods and metadata release" in the Observing request tab and writing your justification in the box that appears. The metadata includes the name and coordinates of the targets. Unless the release date for the metadata is extended, they will become available immediately at CFHT and CADC.

Gender neutrality of Canadians proposals

For Canadian proposals, the name of the PIs will be withheld from the proposals sent to the Canadian TAC to avoid gender bias issues; the top corner of each page will have "(blank)".. The proposal will instead list the name of the authors in random order. However, accepted proposals will be created under the PI's name as previously.

New C3 filter available

A new filter is now available for SITELLE: C3. The Sitelle filters page has links to the ascii file and a graph of the transmission for the new C3 filter.

Available dark time and pressure from Large Programs

Please consult the table of Approximate RA pressure from Large Programs for this semester. The dark time is split between MegaCam and SITELLE and the bright time between ESPaDOnS, WIRCam and SPIRou.

SITELLE PI programs that overlap in RA with the Large Programs will suffer from the competition with the LP. Please take this into account when choosing your targets.

Following a SAC 2014 recommendation: "Beginning with the proposals submitted in the March 2010 round, when CFHT performs its technical evaluation (which is then communicated to the TACs), CFHT will flag any proposal which has conflicts in RA and observing conditions with an existing LP. During their ranking process, the national TACs which are participating in both the conflicting PI programs and LP(s) will provide information to CFHT on the relation and priority of each of those, although agency balancing will continue to be the first decision point for CFHT" (see SAC recommendation #12 from Nov 2009).

Mandatory ETC calculations

The PH1 system has been changed to have users include the values of the SITELLE exposure time calculator into their proposals. Proposals cannot be submitted if this field is not filled. This is not counted toward the page charge.

Effect of (normal) mirror coating degradation on exposure times

The primary mirror (but not the f8 secondary) was recoated in September 2020.

Flux and exposure times provided by the ETC do not take into account mirror degradation. Flux in the blue is affected more than flux in the red; on MegaCam, the loss is about 10% per year in the u-band.

Snapshot programs

All agencies are invited to encourage their community to submit snapshot programs. These programs must be able to accept an Image Quality worse than 1.2" or significant levels of extinction. Snapshot programs are used not only during bad weather conditions but also to fill gaps in the queues when no A, B or C program are available or suitable. Snapshot programs are not counted toward an agency's allocation.

Non-sidereal observations

The non sidereal tracking option (i.e., following a target with non-sidereal rates, but without guiding on stars) is not offered with SITELLE.

Page limit for Canadian proposals

For Canadian proposals: the Science justification is now limited to 2 pages, and the Technical justification to 1 page. For all other agencies, the page limits are 3 pages and 2 pages respectively.

For more information about the submission of your QSO proposal(s), contact the QSO Team qsoteam -=at=-

C - NorthStar [Back to Table of Content]

NorthStar is the Phase 1 tool to submit proposals. This tool is not Latex-based. The scientific and technical justifications, along with references and figures, are uploaded as PDF files, which may be prepared by the PIs on any software they may wish to use. Figures and references may be included with the Scientific and/or the Technical justifications.

Also note the following regarding the list of targets:

D - Applicants [Back to Table of Content]

For each proposal, there can only be one submitter. However, co-I may be invited to view and edit the proposal too. The PI may also be different than the proposer (contact author). Note that if a proposal is accepted, it will get registered in PH2 under the PI's name, not the name of the contact author or the submitter! Each program belongs to its PI and requires the PI's login information in PH2.

E - Justifications [Back to Table of Content]

The Scientific and Technical justifications must be uploaded as PDF files, and have a limit of 2 and 1 page respectively for Canadian proposals, and 3 and 2 pages respectively for all other agencies.

Please use the SITELLE Exposure Time Calculator to calculate the exposure time for each of your target and justify the total integration time requested. You MUST also add overheads, which consist of 3.8 seconds per step of the cube (or, per exposure). Also note that a scan is now limited to 6 hours total, including all overheads.

The justification must mention the SNR needed per exposure and/or needed to obtain the required final depth, and this number must be reflected in the ETC examples provided.

F - Observing Requests [Back to Table of Content]

For SITELLE, you may select QSO Regular programs or QSO Snapshot program. QSO Regular programs include all of the normal QSO programs, with fixed or Solar System objects. Target-of-opportunity (TOO) programs submitted at the same time as all other CFHT proposals may simply be submitted as a QSO regular program. Snapshot Programs must request bad sky conditions and accept a low completion level.

The definition of a snapshot program for SITELLE is the following:

  1. A snapshot program describes valuable science to be obtained on targets observed only in the worse sky conditions (seeing larger than 1.2" in r band, and preferably during non-photometric conditions)
  2. A snapshot program will be scientifically useful even of the completion is low
  3. A snapshot program requests simple observations, sidereal tracking, no monitoring
  4. A snapshot program should preferably include short blocks of observations (one hour or less)
  5. The time allocated for such programs is not accounted for in the statistics of time spent for the different Agencies
  6. The proprietary time for the data is 3 months following the end of the semester.
Note that the chance of such programs to be executed, even partially, during a semester can be quite high.

The probability of observing a specific program depends strongly on the image quality requested versus the statistics of the site. Do not request a better image quality than what is really needed for your program. For guidance, the table below describes the seeing statistics on Mauna Kea. These data are for the R-band and were taken with FOCAM at CFHT between 1993-1995 (more recent statistics confirm these values).

Image Quality (IQ) Frequency
IQ 0.55" 5%
0.55" < IQ 0.65" 25%
0.65" < IQ 0.80" 30%
0.80" < IQ 1.0" 25%
1.0" < IQ 1.2" 15%
IQ > 1.2" 5%

For your information, the table below gives the average weather statistics for Mauna Kea. Note that the "A" semester is usually more affected by bad weather; time lost during the first few months of the winter can be as high as 50% and even more.

Sky Conditions Frequency
Usable Nights ~70%
Lost to Weather ~20-30%
Usable Photometric Nights ~50%

In queue mode, the time requested is in HOURS.

  1. If the total time of your program is fractional (e.g. 32.4 hr.), please indicate so (.4 hr in a queue mode is possible).
  2. In your calculation of integration time, only add 3.8 sec of overheads for each exposure (for readout and other overheads).
  3. Slewing and acquisition of a guide star SHOULD NOT be accounted for in your calculations.
  4. CFHT provides instrumental calibrations (e.g. flats). Please indicate if your observations require photometric standard stars, and if any other on-sky calibration are also needed. The "Calibration Requirements" box may be used to present those calibrations.

Any time constraint or scheduling constraint must be indicated in the proposal: the need for a certain number of consecutive nights, the need for long blocks of time (for example, 8 hours) per night, the need to coordinate CFHT observations with observations taken by another telescope, etc.

By default, the proprietary period of QSO data extends to 1 year + 1 month starting at the end of the QSO semester. If an extension is requested and approved by TAC, a new date will be set for this program through the QSO system. The release date for the data is indicated in the fits headers by the keyword REL_DATE. For snapshot programs, the proprietary time is 3 months following the end of the semester.

G - Target list and declination limits [Back to Table of Content]

Besides a list of targets with coordinates, SITELLE proposals may include the Magnitude of each target or the diameter of the field. This information will be used to evaluate the technical feasibility of each proposal. Note that SITELLE cannot observe at an airmass higher than 1.51. The declination of the target must be between [-30, 63.0] degrees.

H - Additional issues [Back to Table of Content]

The Additional issues tab is used to link various proposals together, if need be.

Z - Check list [Back to Table of Content]

Before submitting your proposal, please make sure that:

Need More Information?
Contact the QSO Team at
qsoteam -=at=-