The GHOST project commissioning has begun, with the Canadian and Australian teams able to travel to the summit following the easing of COVID-19 related restrictions. Optical bench assembly has begun, with alignment tests scheduled for late April. Twilight tests are to take place in mid-May. On-sky science commissioning is planned to take place in mid-late June, 2022.
A new webpage with information on the current status of the GMOS-N detector array is now available here. The webpage provides details on the recent hot column features (see March 10 announcement) and updated recommendations for dither strategies to minimize the impact of the hot columns on science data. Any future updates from the ongoing characterization of the hot columns will be posted on this webpage.
As of July 2022 the noise problem on CCD2 and CCD1 persists.
The GMOS-N detector issue reported on March 2 has largely been resolved by the full thermal cycle performed between March 2 and 3. The extended bright columns on amplifiers 7 and 12 are no longer present. The narrow bad column of hot pixels on amplifier 5 persists and saturates in longer science exposures. The following figure shows the hot column in an overscan-subtracted bias image (as marked by the blue arrow).
Multi object spectroscopy with Flamingos-2 is now offered via the latest Fast Turnaround Call for proposals and also for regular queue in 2022B. Details on this capability can be seen here.
The GMOS-N detector has shown new bias features since an uncontrolled warm-up of the detector on February 26, 2022 . These features consist of a narrow bright column on amplifier 5, and broader bright columns on amplifiers 7 and 12. As a first measure to address this new issue, a full thermal cycle of the detector is being performed starting from today. GMOS will be unavailable for the next couple of nights until the thermal cycle is complete.
GMOS-S is unavailable due to the re-appearance of the CTE problem on CCD1, plus high noise structure on CCD2. Troubleshooting started on Monday and is currently ongoing.
F-2 was successfully checked on January 26th after an intevention that lasted for most of January. New JH and HK gratings were installed and its performance will be assessed in the following days. Additionally, the J_low filter is now permanently installed.
An intervention of Flamingos-2 is planned between January 3rd and 21st where the instrument will be offline. The following tasks are planned:
MOS wheel check and preventive work.
Replace the JH/HK spectroscopic filters with higher throughput ones.
Modify the Lyot wheel to allow the installation of the J-low and Y filters instead of the Hartmann masks.
Increase the number of layers in the dewars insulation, to allow more thermal stability.
After a thermal cycle performed over the weekend, the detector amplifier #5 is back to its normal perfromance. CCD1 CTE is also nominal, and OIWFS performance is OK after the successful repair that had been performed during September. Therefore GMOS-S is back at full capacity.