MMT and Magellan Infrared Spectrograph

ABSTRACT.The MMT and Magellan infrared spectrograph (MMIRS) is a cryogenic multiple-slit spectrograph operating in the wavelength range 0.9–2.4 μmμm. The refractive optics of MMIRS offer a 6′.9 × 6′.9  6′.9×6′.9 field of view for imaging with a spatial resolution of 0.2 arcsec pixel-10.2  arcsec pixel-1 on a HAWAII-2 array. For spectroscopy, MMIRS can be used with long slits up to 6′.9 long, or with custom slit masks having slitlets distributed over a 4′ × 6′.9  4′×6′.9 area. A range of dispersers offer spectral resolutions of 800–3000. MMIRS is designed to be used at the f/5 foci of the MMT or Magellan Clay 6.5 m telescopes. MMIRS was commissioned in 2009 at the MMT and has been in routine operation at the Magellan Clay Telescope since 2010. MMIRS is being used for a wide range of scientific investigations from exoplanet atmospheres to Lyαα emitters.