LISA: A Low Resolution MIR/FIR Imaging Spectrograph for SOFIA

LISA is a proposed low resolution (R~15-30) imaging spectrometer for SOFIA, the American-German Stratospheric Observatory for Far Infrared Astronomy. Covering the wavelength range from 40micron to 220micron with three channels, LISA provides diffraction limited spectroscopy for each pixel within a rectangular field of view (FOV). The FOV sizes for the channels are 18x11 arcsec for 40 to 70micron, 32x19arcsec for 70-120 micron, and 22x22arcsec for 120-220micron, each channel upgradable to about twice the linear size. LISA will be able to address a variety of astrophysical topic, in particular on faint targets. Spatially resolved temperature distribution of dust emission will be studied in the environments of young and evolved stars, star forming regions, as well as in nuclear regions of nearby galaxies. Spectral energy distributions (SEDs) of distant galaxies will be determined in search for cold gas components. LISA's spectral resolution will be high enough to search for broad spectral features (e.g. PAHs, ices). The optical design, the mechanical layout, the estimated sensitivity, and the scientific potential of such an instrument is briefly discussed.