NICS - R2 98.7 Grism

The 1mic, Js, J and H medium resolution spectra are obtained using a single grism, namely a 98.7 lines/mm blaze=63.5 deg transmission grating glued on the hypotenuse of a 60 deg prism of IRGn6 glass, working in fifth, fourth and third order, respectively.

The order sorters are the same 1mic, Js, J and H broad band filters used for imaging. Please note that the Js filter is narrower than J but has a much higher transmission and, therefore, should be used in all cases when the spectral coverage offered by Js is sufficient for the purposes of the program.

For any comments please contact Vania Lorenzi.