FAR-INFRARED LINE MAPPER (FILM) ON THE INFRARED TELESCOPE IN-SPACE

We have developed a Far-Infrared Line Mapper (FILM) as one of the four focal plane instruments on the Infrared Telescope in Space (IRTS). Th e FILM is a grating spectrometer designed to simultaneously measure [C II] 158 mum and [O I] 63 mum line intensities and continuum emission near the [C II] line with spatial resolution of 8 arcmin. Very high se nsitivity and accuracy are achieved by using stressed and unstressed G e:Ga detectors at 1.8 K with a helium cooled telescope and by using a spectral scanner to distinguish the line emission from the continuum e mission. Line intensities of the [C II] and the [O I] will be mapped o ver 10% of the sky with much higher sensitivity than the previous surv ey measurements.