Ground-based commissioning of FLITECAM

Abstract

FLITECAM is a 1-5 micron spectrometer and camera developed at UCLA for NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA). On SOFIA, FLITECAM will take advantage of lower backgrounds from 3-5 microns and will provide access to spectral regions completely or partially absorbed by water vapor at even the best ground-based sites. FLITECAM employs large cryogenic optics and an ALADDIN III 1024 × 1024 InSb detector to inscribe an 8 arcminute field of view with 0.48 arcsec/pixel spatial resolution. The optical components are cooled with liquid nitrogen and a liquid helium reservoir is used to establish an operational temperature of 30 K for the InSb array. FLITECAM has two primary observing modes, imaging and spectroscopy. A pupil-viewing mode, for examination of the primary mirror surface, and a high-speed snapshot mode for occultation observations are also provided. Ground-based commissioning of the instrument using the Shane 3-meter telescope at UCO/Lick Observatory has been completed successfully. In addition to broad-band filters, the imaging mode accommodates several narrow-band filters. A data reduction pipeline processes dithered image sets in real-time during the flight. The grism spectroscopy mode employs three direct-ruled KRS-5 grisms and fixed slits of either 1 × 60 or 2 × 60 to yield resolving powers (FWHM) of R~1700 and 900 respectively. Observations are scripted using AORs (Astronomical Observation Requests) in both modes. A pilot survey of 3.3 micron emission in planetary nebulae performed with FLITECAM at UCO/Lick Observatory demonstrates the potential of the grism mode.