Spectroscopy

The NOTCam calibration unit for spectroscopy (three lamps of halogen, argon and xenon mounted on the inside of the telescope baffle lid), is now under full computer control and the status of the lamps is included in the FITS headers. Some extra safety aspects were added to the TCS where it is not allowed to switch on the TV if any of the lamps is on.

A script similar to the one already used for ALFOSC to take calibration exposures has been tested and released. As part of the observing sequence, the mirror cover needs to be closed and opened afterwards, which is included in the script. For safety, the script will not open the mirror covers after the calibration exposure unless the upper hatch is already open, and it will not switch on the guide TV unless the mirror cover is open. The documentation has been updated to include the new usage of the calibration lamps.

The status of the lamps we need to be added to the NOTCam user interface such that it is easier to see if the lamps are on or not. We also plan to include the status of the lamps in the mirror cover also for other instruments as the lamps are always there independent of which instrument is mounted.

The design for the new low-resolution ($R\sim700$) grisms was made and a quote was obtained for the two grisms of 22000 USD. The 2 order sorter filters that would need to be bought would add a further $\sim$4000 Euros. Given the price we tried to re-asses if adding this option was really worth the money. Specifically, several potential users were contacted directly about if they were still interested and if they had any specific preference for one of the two grisms. The clear preference of the users seems to be for the short-wavelength range and we are looking if we can find a cheaper supplier.

Thomas Augusteijn 2010-11-19