The development of the spectrometer LonGSp (Longslit Gornergrat
Spectrometer) was part of a project aimed at providing
the 1.5-m Infrared Telescope at Gornergrat (TIRGO)
with a new series of instruments based on
NICMOS3 detectors. The infrared (IR) camera, ARNICA, developed in the context
of this project is described in Lisi et al. (1995).
LonGSp is an upgrade of GoSpec (Lisi et al. 1990), the IR spectrometer
operating at TIRGO since October 1988.
Thanks to the NICMOS detector, the new spectrometer
enables longslit spectroscopy with background
limited performance (BLP). The GoSpec characteristics of compactness and
simplicity are maintained in the new instrument.
Only a subsection of the engineering grade array (
pixels) is
used. A description of the optics, cryogenics, and
mechanics is presented in Sects. 2 (click here) and 3 (click here); the electronics,
software and the performance of the detector are presented in
Sects. 4 (click here) and 5 (click here). Finally, in Sect. 6 (click here) we present
details regarding the observations and data reduction, and in Sect.
7 (click here) the results of the first tests at the telescope.