Spectroscopy

A new, non-IDL version, of the software to align slits and grisms was developed and implemented.

New high-quality slits have been purchased and installed. Some of the old bad ones were discarded and replaced. We now have full sets of horizontal, vertical and offset-vertical slits. The vertical slits allow high time-resolution spectroscopy and tuning of the sampled wavelength region. The vertical 0.5 arcsec slit has been scratched and will be replaced.

ALFOSC spectroscopic quality-control routines were moved to the dedicated reduction computer and grisms #16 and #17 have been added to the exposure time calculator.

Some intermittent problems have been reported with the He calibration lamp which we now believe is due to a problem in the electronics, not the new lamps and starters that were suspected first. A solution is being worked on.

With the new camera there seems to be a increase in the amount of ghosts seen when observing bright sources. This is likely related to the poor efficiency of the coating of the camera in the red, i.e., the large amount of light that is reflected. The amount of ghosting for the different grisms will be mapped.