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Session 9 - SOFIA and IR Instrumentation.
Display session, Wednesday, January 07
An integral field spectrograph is currently under construction to operate at near-infrared wavelengths on the 200-inch Telescope at Palomar. The spectrograph incorporates an eight-element, all-reflective image slicer to transform the two-dimensional field into a pair of long slits. The field of view is roughly 6''\times 10'' on the sky, covered by eight 0.67''\times 10'' slits. Diamond-turned aluminum surfaces form the optical elements in the all-aluminum image slicer assembly. The movable reflection grating has two faces, delivering spectral resolutions of 450 and 200 km s^-1. The spectrograph, mounted at the f/70 Cassegrain focus, produces a dispersed f/70 image plane that is fed into an existing near-infrared camera. While the design favors the use of the camera employing a 256\times256 HgCdTe array, a similar camera with a 256\times256 InSb array may also be used, extending the wavelength coverage of the spectrograph out to 5\mum. The spectral coverage in the high resolution mode is > 4000 km s^-1, with roughly double that in the low resolution mode. A mirror can be placed in front of the grating providing the capability for direct imaging through the spectrograph in order to facilitate target acquisition.
Program listing for Wednesday