next up previous contents
Next: Intermediate Dispersion Spectrograph Up: Spectroscopic instruments Previous: Calibration facilities

Grisms on the JKT CCD camera


The JKT grisms are little used, and potential users should check their availability with support staff before applying to use them. The JKT CCD camera and its dedicated A&G unit are described in detail in Sections gif and gif. In addition to using this as an imaging instrument, it is possible to carry out low resolution slitless spectroscopy with one of two grisms. The grisms are identical except for their blaze; one is blue and the other red. The efficiency of both of these grisms as a function of wavelength is plotted in Figure gif.


Figure: Efficiency curves for the JKT CCD camera grisms

When used in first order, the dispersion is 11.2 Åpixel on the Tektronix chip (pixel = 24 microns), so that with 1 arcsec seeing the spectral resolution is about 32 Å (FWHM). Note that when observing in the red, it is necessary to use a colour filter to remove second order blue light.

Tue Aug 15 16:42:46 BST 1995