|2016, August 23:
First article on SV data submitted ! Available here. SV processed data are publicly available here.
|2016, February 3:
The document outlining the latest on the instrument performance is now available here.
|2015, January 13:
The Science Verification phase of SITELLE was a big success! Mahalo to all the team involved in the achivement! Several objects were observed and are now being analyzed to provide PIs a current update of the instrument. Stay tuned!
|2015, August 10:
SITELLE had another successful run on the telescope! Besides some wonderful spectral cubes that we will show very soon, important milestones have been reached. First, the Exposure Time Calculator (ETC) has been validated thanks to the observations of standard stars (GD248, G24-9). The ETC predicts counts within 5-10% of the observations for all filters except SN1, though we know the reflectivity of the mirrors changes quickly with time on the blue. Second, using amazing observations of M57, we tested some large Optical Path Difference (OPD), i.e. resolution. At the position of the Hα line, FWHM of 5.54 cm-1 were expected and we measured a width only 3-4% larger. This means that SITELLE meets the expectation at least up to a resolving power of about 2800. Third, the noise levels of the ETC were also validated using observations of NGC628 with the SN3 filter. Predicted levels at 3σ are very close to those observed using a binning of 1x1 (20% difference), 2x2 (less than 10% difference), and 3x3 (no difference).
SITELLE will be offered for the upcoming call for proposals (semester 2016A) with the possibility to ask for "shared-risk" time during 2015B. SITELLE is also offered in the call for the Large Programs 2017-2019.
|2015, July 9:
SITELLE has seen its first photons from the skies of Maunakea! For the past three nights, SITELLE has been mounted on the CFH telescope, going through a first series of tests. While a few minor adjustments are necessary, all lights are green for a second run on the telescope at the beginning of August.
SITELLE mounted on the CFHT
A part of the Veil Nebula NGC6992 as seen with SITELLE
|2015, June 10:
SITELLE is at CFHT! It was shipped to Hilo via Honolulu by plane, and then carefully driven to the summit of Maunakea, where it was unpacked by the crew like children unpack their birthday gifts. A video that summarizes the events of the day can be found on our Vimeo channel.
A happy project manager, Marc Baril, with SITELLE on the fifth floor at CFHT
SITELLE has been moved from ABB to U Laval for the cold tests, which are part of the acceptance tests. Marc Baril from CFHT will be there for at least a couple of weeks.
|2014, July 15:
The ME in the near UV appears to be excellent. SITELLE's efficiency (modulated power/total power, which takes into account the two output ports) is around 70% at 370 nm. The UV source used for the measurements is very weak and the small amount of parasitic light in the lab caused problems, however the filter was a great help. There was some contamination on the filter (fingerprint? dirty tissue?) when it was installed in the clean room, though nothing was seen on the images. Two other LEDs are being purchased to obtain more flux (and better quality measurements).
The instrument has undergone much testing since March and is essentially materially complete with all of its electronics boxes populated and cables fabricated. Testing in March and April focused on verifying the effect of vibrations on instrument performance as determined by looking at the modulation efficiency (ME) near the zero-path-difference (ZPD) position of the interferometer. The ME measured at 534 nm reaches over 85% with the cryo-coolers powered on. This closely meets the goal desired for the instrument and is well above the requirement at 534 nm of 73% ME. The modifications made to the beam splitter mount had a significant effect on the optical path difference (OPD) stability, allowing the ME goal to be reached. However, the ME at 370 nm, the short wavelength extreme of the instrument, has yet to be measured. If the ME is good at this wavelength it will almost certainly meet requirement at all other wavelengths given what is known about the spectral reflectance (R) and transmission (T) of the beam-splitter (i.e. a factor of 4RT contributes to the ME).
Marc Baril travelled to ABB for ten days of work at the beginning of April (see previous News entry); at this time repairs were made to one leaking camera cryostat and the sensitivity of the instrument to vibrations was investigated. Implementation of the control software for the instrument by Jim Thomas was done in May, firstly working at CFHT and then at ABB for one week. Marc returned to ABB for another ten days to work on testing instrument performance and develop scripts and reduction tools required for the final testing.
Early in this week of work it was noticed that the ME was degrading as the distance of the scanning mirror from ZPD increased much more rapidly than expected. The effect is worse on one camera, with the ME dropping to 30% for a 1 mm OPD on that camera. Furthermore, there is a noticeable drop in the ME across the field of view, with the ME being lower where the fringes are more closely spaced. Note that the spatial frequency of the fringes on the detector was well below the regime where the modulation transfer function of the combined optics and detector would affect the ME. Stopping down the input pupil of the output camera lenses improved the differential ME drop between the cameras, however it did not improve the overall ME degradation, using the more well-behaved camera as reference.
Rotation of one of the cameras led to an improvement in the ME suggesting that a tilt was present somewhere in the output optics. There is also likely to be a strong effect to the overall ME function with OPD due to the manner in which the instrument is being illuminated during the tests (the pupil is over-filled by the integrating sphere at the instrument input). ABB is working with Denis Brousseau at Laval to resolve these issues while personnel at CFHT provide feedback and suggestions. Until this problem is resolved, testing cannot continue and we anticipate that testing in the cold will not commence until late August at the earliest.
The preferred option for cold testing of the instrument is for ABB to install a cold room at their facility that they would rent to Laval for its use as a way to recuperate some of the capital costs for its construction. Testing at ABB holds several advantages; cleanliness of the room, ready availability of personnel and test equipment, access to the instrument is completely under ABB’s control and the instrument does not have to be crated up for shipping to Laval (a very time consuming process). The second option is to use the civil engineering cold testing facility at Laval.
If testing happens in September, the earliest shipping of the instrument to CFHT would be in October.
Marc Baril travelled to ABB for ten days of work at the beginning of April. This trip was very useful in providing a more clear understanding of the functioning of the instrument, it’s sensitivity to vibrations and acoustic noise, and to settle details of what will be required for the acceptance testing.
One problem that has arisen with the delayed schedule is that the cold room originally identified for testing and final tuning of the instrument is no longer available on a time-scale that is acceptable to the project team. ABB is re-evaluating the possible options to find a solution that gets SITELLE to CFHT by the end of the summer.
Several infrastructure (hardware and software) items remain to be implemented at CFHT prior to SITELLE’s arrival, however it is not anticipated that the schedule for these items will impede commissioning readiness of the instrument.
The first two SITELLE filters received at CFHT (668nm center 34 nm wide, and the 593.6 center 63 nm wide). A third filter (H-alpha) was received in April at Laval by Laurent Drissen
532 nm laser fringe image, 80 metrology fringes away from ZPD (lab image used to determine ME). Taken with the SITELLE science cameras (channel 1 at left, channel 2 at right).
Julie Mandar checking for light leaks prior to ME measurements. View of the lower optical output. Metrology laser pickup fibers can be seen directly above her right hand. CCD cryostat is the gold structure near the bottom – cryo lines heading upward toward the right.
View of the instrument showing both output ports.
Instrument on its handling gantry - the relatively large size of the instrument (for CFHT) is more fully grasped in this image.
|2014, February 18: || ABB places order for the parts used to modify the beam splitter cell. |
|2014, February 6: || ABB implements a new, faster alignment method using 3 white light detectors. |
|2014, January 27: || ABB obtains go-ahead to proceed with changes required to the beam-splitter mounting. |
|2013, December 20: || ABB reports that the beam-splitter mounting best explains the problems seen with the vibrations. |
|2013, November 29: || Modifications improve the stability insufficiently; the wavefront error is now 55 nm RMS. |
|2013, November 13: || The stiffening process involving inserting adhesive in the flex cylinder gaps is successful… but too successful, the range of motion is reduced to 15 $µm$ from 45 $µm$. Adhesive is removed from the gaps to increase the range of the motion. |
|2013, October 29: || ABB decides to stiffen the dynamic mirror assembly (DA) in an attempt to reduce the sensitivity to vibrations. |
|2013, October 15: || ABB reports problems achieving the desired stability of the wavefront when the camera cooling is enabled. In the quiet lab 7$±$2 nm RMS wavefront error is detected, whereas with the camera cooling enabled 76$±$5 nm is seen. |
|2013, September 27: || Denis Brousseau releases the optical test report for the camera and collimator assemblies. Total lens transmission is less than expected. |
|2013, August 15: || ABB starts work on closing the loop on the interferometer servo. |
|2013, August 12-16: || Integration of the CCD cameras and optics at Laval - beginning of the optics testing. |
|2013, July: || ABB modifies MINT3 board with new DAC to achieve desired servo control rate. ABB is having issues with vibrations in the lab; modifies the support gantry with springs to isolate the instrument from building vibrations. |
|2013, July 22: || Cameras ship out to U. Laval. Everything is within specifications except for the noise on one amplifier when operated with no binning. |
|2013, June 26: || First-light engineering achieved with the science arrays. |
|2013, June 14: || CCD testing of the good engineering array indicates that specifications were comfortably met on the read noise for all the binning modes. The CCD read time is just over spec in 1x1 mode. |
|2013, June 7: || Cooling plate completed and tested for leaks. |
|2013, June 3: || Science grade CCDs arrive at CFHT. |
|2013, May 31: || Interferometer is aligned and the white light ZPD is found. |
|2013, May 30: || Laval (Denis Brousseau, Simon Thibault) begins tests on the collimating lens assembly. |
|2013, May 17: || Optical tubes completed at Université de Montréal |
|2013, May 12-14: || "Science with SITELLE" workshop held at Wendake, Québec. To access the presentations go to: http://www.craq-astro.ca/sitelle/index.php |
|2013, April 30: || E2V delivers CCDs to U. de Montréal. |
|2013, April: || Real beamsplitter bonded in its cell. |
|2013, March: || All lenses arrive at U. Laval, except for both C3 lenses in the camera tube that were damaged in manufacture (RMI). |
|2013, February 28: || Proof of concept cementing of the dummy beamsplitter in its cell is brought within specification after three attempts, modification of the cementing process and increasing the internal diameter of the cell. |
|2013, February: || Instrument support structure is assembled. |
|2013, January: || Interferometer enclosure completed. |
|2012, December 20: || Zygo completes the post-optical contacting polishing and applies AR coatings; the fully completed part is within specifications. |
|2012, December: || Dynamic mirror assembly (DA) fabrication completed. |
|2012, December: || Successful pull test on the cemented aluminum and carbon fiber tube segments performed. |
|2012, December: || Castings for the instrument structure delivered |
|2012, December 4: || Beginning of discussions about the redefinition of the CCD order with E2V to use deep depletion arrays with broadband coatings. |
|2012, November 29: || Zygo reports a successful optical contacting between the two beam splitter halves. |
|2012, November 14: || Zygo obtains a much better coating for the beam splitter (correcting the non-compliance at 420 nm) and are given the go-ahead to coat the actual part. |
|2012, October 11: || Zygo successfully achieves optical contact on a test sample for the beam-splitter. |
|2012, October 10: || ABB officially begins its manufacturing phase after meeting with the Laval and Montreal SITELLE teams. |
|2012, September: || Zygo obtains a partially successful beam splitter coating; strong non-compliance at 420 nm. |
|2012, September: || Zygo manufactured mirrors completed within specifications. |
|2012, June: || SITELLE team presents papers at SPIE. |
|2012, June 25: || Critical design review at ABB, CFHT in attendance. |
|2012, June 19: || Fabrication error with the E2V CCDs pushes delivery to end of 2012. |
|2012, February 22nd and 28: || Preliminary design review at ABB (CFHT telecon) |
|2012, February 16: || CCD camera design review meeting at CFHT (ABB/Laval telecon) |
|2011, October 31: || Final release of the Science Based Requirements document |
|2011, October 18 & 24: || ABB led kick-off meeting (CFHT telecon) and conceptual design review. |
|2011, September 12: || U. Laval and ABB-Bomem sign the work contract for SITELLE. |
|2011, May 27: || CFHT kickoff meeting for the CCD camera work. |
|2011, February 23: || Meeting at ABB between CFHT (Marc Baril and Jim Thomas) and ABB project leads to discuss project logistics and to review compliance with the CFHT IDS requirements. |
|2010, June: || SITELLE team presents the project at SPIE. |
|2008, April 1: || SITELLE selected to proceed with feasibility/conceptual study for a guest instrument at CFHT. SITELLE awarded CFHT start-up funds |
|2007, October: || The SITELLE team submits their proposal in response to the "CFHT New Instrumentation" call for proposals for the "2013+ Horizon". |