Science instruments for the Giant Magellan Telescope

Abstract

We describe the development status of the first generation of science instruments for the Giant Magellan Telescope (GMT) and the very broad range of first-light capabilities that they will deliver. The first-generation suite includes visible and infrared spectrographs delivering a wide range of spectral resolution; an infrared, diffraction-limited imager; and a visible to near-infrared, extreme adaptive optics coronagraphic imager and spectrograph. G-CLEF, a visible light echelle designed for broad scientific use and for precision radial velocity measurements, is in fabrication. Instruments in the final design phase as of this publication, include: GMACS, a high-throughput, wide-field, multi-object spectrograph; GMTNIRS, a near- to thermal-infrared echelle spectrograph utilizing silicon immersion gratings to achieve a very compact design that delivers a fixed-format spectrum from 1-5μm in a single exposure; and GMagAO-X, which has internal deformable mirrors coupled with a coronagraph to deliver extreme-AO resolution, high contrast imaging and spectroscopy of extrasolar planets, including nearby potentially habitable terrestrial worlds in reflected light. GMTIFS, a diffraction-limited, near-infrared, integral- field imager and spectrograph is in preliminary design. The first-generation suite also includes a robotic fiber-feeding system called MANIFEST that will enable spectroscopy over the 20 arcmin field of view of the telescope and can feed GMACS, G-CLEF, and future seeing-limited near-infrared spectrographs. We also discuss the visible and infrared cameras (called ComCam and AOTC, respectively) that will be used for alignment, verification, and commissioning of the active and adaptive optics modes of the telescope, as well as enable early science and outreach activities. Finally, we describe SuperFIRE, a seeing-limited infrared spectrograph undergoing a feasibility study that will enable key science involving the high redshift universe, low mass stars, dust-obscured environments and broadband transients before the GMT adaptive optics is fully commissioned.