Spectroscopy

NOTCam spectroscopy mode uses the 3 lamps installed on the inside of the baffle lid as a calibration unit. The Argon lamp usually switches on with a delay, but the delay time is variable. The Argon lamp has been exchanged for a new one, but the problem persists. No correlation with dome temperature has been found. The script for night-time in-situ calibrations, ``notcam.easy-calib'', has been programmed to switch on the lamp as early as possible (as soon as the TV is switched off, while mirror covers are closing), and to do Argon arcs for all setups first. But even in this mode, it happens that Argon exposures are taken with the lamp actually off. Tests show that the lamp can come on relatively fast, i.e. within a few seconds, or relatively slow, up to 2 minutes. There seems to be no way to predict this. The introduction of an extra "wait" for Argon in the script will cause extra overheads and may not always be needed. The script will be modified to take a test exposure and verify that the lamp is on before taking the calibration data, and this loop should be started already while the mirror cover is closing.

Acquiring the target on the slit for NOTCam spectroscopy has up to now been done in a relatively manual way compared to the acquisition scripts available for ALFOSC and FIES. The procedure for NOTCam has two extra complications compared to optical spectroscopy: 1) sky subtraction may be needed to see the target in the acquisition image and 2) flexure of the instrument requires the slit position to be determined at every pointing. The plan is to complete and implement the ``"notcam.acquisition'' script in the current semester.