The Goddard Cooled Grating Spectrometer
Session 34 -- Airbourne Astronomy
Display presentation, Tuesday, 9:30-6:30, Pauley Room

## [34.19] The Goddard Cooled Grating Spectrometer

S. C. Casey (NAS/NRC Resident Research Associate, NASA GSFC), S. H. Moseley (Lab. for Astronomy and Solar Physics, NASA GSFC), K. W. Chan (Dept. of Astronomy, Univ. of Maryland), R. F. Loewenstein (Yerkes Observatory, Univ. of Chicago)

We describe a far-infrared spectrometer using monolithic silicon bolometer arrays for observations aboard the Kuiper Airborne Observatory. The instrument consists of an He-cooled grating spectrometer with two abutted 24-channel linear arrays. Over wavelength ranges of 15 - 30 and 30 - 50 $\mu$m, the spectral resolution is selectable within a range of 50 - 200 depending upon the choice of order sorting filter, grating, and linear detector array. The bolometers arrays consist of 24 free standing detector elements with individual detector widths of 0.5 and 1.0 mm etched from 3" silicon wafers at GSFC. Since the bolometers themselves are capable of detecting radiation over a broad wavelength range, the spectrometer's passband is determined soley by the selection of filters and gratings. To optimize the instrument's sensitivity to point sources and narrow line sources, the spectrometer employs a multi-position aperture slide and an adjustable grating table. The spectrophotometer has recently been used to observe SN1987A, Cas A, the outflows of dusty AGB stars, and active galactic nuclei.