1999PASP..111.1176M

We present the design, construction, and performance of a near-infrared integral field spectrograph now in operation at the Palomar Observatory 200 inch telescope. The spectrograph acts as a front end to one of two existing infrared cameras, covering the 1-2.5 µm and 1-5 µm wavelength ranges. An all-aluminum image slicer splits the 5".4x9".6 field of view into eight slits, feeding two independent spectrographs within the same dewar. Spectra are simultaneously obtained for all points within the field, with seeing-limited spatial resolution. Two resolution modes of R~1300 and R~600 are available, as well as a broadband imaging mode for photometry and target acquisition. The spectrograph was first operated on the 200 inch telescope in 1998 September. Performance has been as predicted, with a total system throughput of ∼22% from the top of the atmosphere to electron counts. Sensitivity is estimated to allow detection of a K=18 mag (0.04 mJy) continuum point source at the 5 σ level in 1 hr of integration at the high-resolution setting. Example data from the spectrograph are presented here.