GMOS tutorial on flexure-induced wavelength shift correction using sky lines
Flexure effects within GMOS can result in wavelength zeropoint shifts if the on-sky science data are wavelength-calibrated using daytime CuAr arc exposures.
Flexure effects within GMOS can result in wavelength zeropoint shifts if the on-sky science data are wavelength-calibrated using daytime CuAr arc exposures.
In early April 2024, the GNIRS camera turret experienced a mechanical issue, likely due to the dragging of a bearing that helps drive the movement of the turret. It has been assessed that GNIRS could no longer reliably shift between its long and short cameras. A soft lock on the camera turret has been put in place, which fixes the location of the turret to the short blue camera.
As part of the Gemini Instrument Upgrade Program GNIRS has gained two new optical sub-systems, namely the LR-IFU and the HR-IFU. The commissioning of both IFUs has now been completed.
GNIRS recently began showing an issue that affects every 8th column on the top right quadrant of the detector, an issue that impacts all GNIRS modes. This issue first appeared on the 25th of October, 2022. Investigations to mitigate or fix the issue are currently ongoing. For the time being, PIs are advised to consider all pixels associated with these columns as bad pixels and not to use them for science and/or calibrations.
After the successful upgrade of two of the three GMOS-S CCDs, the instrument is back on the telescope and undergoing recommissioning. The long-slit mode has been released for taking science data. However, updates for the data reduction packages in IRAF and DRAGONS are pending testing after the full commissioning data set has been collected and will likely not be available until the May/June timeframe.
GMOS-S will be removed from the telescope on Friday, July 21st for the CCDs intervention, with the purpose of replacing the faulty CCD2.
The instrument is scheduled to come back during late August for the commissioning of the upgraded detector array, and expected to be available for Science by September.
The GMOS-N B600 grating sensitivity has recently degraded significantly. This overall degradation is in addition to the blue sensitivity loss reported previously. Since the new B480 grating is now available for GMOS-N, we recommend changing B600 programs to the B480 grating. The B480 grating offers a wider wavelength coverage than B600 at a a slightly reduced spectral resolution.
GNIRS has been reinstalled on the telescope after the extended shutdown and is ready for science use as of June 6, 2023. All slit spectral modes along with imaging are available. Both the Low Resolution and High Resolution IFUs are now installed and are undergoing commissioning. They will be released for science use at a later date.
We are pleased to present the first GHOST science observations that have been reduced with the GHOST pipeline. We are releasing the spectrum of XX Oph (Be + Red Supergiant; V= 8.59-10.2 mag) as an example to showcase the spectral range, spectral resolution, and overall quality of data that GHOST can provide in standard resolution mode (R=50000; with a total integration time of 240s, and a wavelength range of 347 to 1060nm).
GHOST has not yet been fully commissioned and information such as sensitivities is pending. For this reason GHOST is not offered as an instrument for regular science in 23B. We expect most modes to be fully commissioned late 23A, and for there to be a special Call for proposals in 23B. We will post an announcement as soon as we have more details on the special call in 23B.