NICS - IR-ENG Filters

The narrow band filters were manufactured by IR-Eng for the consortium of astronomers headed by Alan Tokunaga. They are mounted inside NICS tilted by about 3 degrees. Their transmission was measured directly inside the instrument by taking a series of spectra of a halogen lamp without and with the filter inserted before the AMICI, IJ, JH, JK' and HK dispersers. No significant (>10-4) out-of-band leak was found within the 0.8-2.6 µm wavelength range.
The resulting transmission curves, measured at a temperature of about 78 K, are available in the following ASCII files.

Please note that in each file there are two entries which are the transmission measured at the center and at the upper edge of the field, i.e. at an incidence angle of 3 and 6 degrees, respectively.

For any comments please contact Francesca Ghinassi.