
308 12. Spectrometry: Definitions and Basic Principles
12.2.
SLIT SPECTROMETERS
A general layout of a slit spectrometer in the most commonly used arrange-
ment is shown in Fig. 12.4. Elements of
the
spectrometer include an entrance slit
of width w and height h at the telescope focus, collimator and camera optics to
reimage the entrance slit, and a disperser whose angular dispersion is A.
Collimator and camera optics have focal lengths f^ and fi, respectively, with a
reimaged slit of width w' and height h' at the camera focus.
The entrance slit subtends angles 0 and </>' on the sky and da and da' at the
collimator, where 0 = w//,
(f)'
= h/f,