Grism Spectroscopy with FLITECAM

摘要

FLITECAM, a near-infrared instrument being developed at the UCLA Infrared lab, will be the first light infrared instrument for NASA's SOFIA aircraft. In addition to its imaging capability, FLITECAM has been equipped with three direct-ruled KRS-5 grisms, allowing observations in 9 spectral bands, and giving nearly continuous spectral coverage from 1 to 5.5 microns. The design favors regions of the spectrum that are heavily attenuated except at high altitudes. The grisms are used with a dual-width long slit to yield a spectral resolution of R～1700 at high resolution and R～ 900 at low resolution. This resolution is better than that of the IRAS, ISO or KAO spectrometers, and covers a spectral regime left unsampled by the Spitzer Space Telescope. When used on the SOFIA, FLITECAM's spectroscopic mode will allow astronomical investigation of near-infrared features at a low water vapor overburden. The grism spectroscopic mode has been demonstrated on the Shane 120 inch telescope at Lick Observatory by observations of astronomical targets of interest, especially the PAH feature at 3.3 microns in HII regions and young planetary nebulae.