GMTNIRS: the high resolution near-IR spectrograph for the Giant Magellan Telescope

We present a conceptual design for a powerful, high-resolution near-infrared spectrograph for the Giant Magellan Telescope (GMT). This instrument, the Giant Magellan Telescope Near-Infrared Spectrograph (GMTNIRS), uses silicon immersion gratings as the primary dispersing elements. The design has two modules, one for 1.1-2.4 μm for use under native seeing conditions and one for 3-5.5 μm to be used with adaptive optics. The resulting design is physically compact and allows us to cover entire infrared atmospheric windows in a single exposure with resolving powers up to 100,000.