The Infrared Imaging Spectrograph (IRIS) for TMT: instrument overview

Abstract

We present an overview of the design of IRIS, an infrared (0.84 -2.4 micron) integral field spectrograph and imaging camera for the Thirty Meter Telescope (TMT). With extremely low wavefront error (<30 nm) and on-board wavefront sensors, IRIS will take advantage of the high angular resolution of the narrow field infrared adaptive optics system (NFIRAOS) to dissect the sky at the diffraction limit of the 30-meter apertme. With a primary spectral resolution of 4000 and spatial sampling starting at 4 milliarcseconds, the instrument will create an unparalleled ability to explore high redshift galaxies, the Galactic center, star forming regions and virtually any astrophysical object. This paper summarizes the entire design and basic capabilities. Among the design innovations is the combination of lenslet and slicer integral field units, new 4Kx4k detectors, extremely precise atmospheric dispersion correction, infrared wavefront sensors, and a very large vacuum cryogenic system.

The InfraRed Imaging Spectrograph (IRIS) for TMT: photometric characterization of anisoplanatic PSFs and testing of PSF-Reconstruction via AIROPA

“…The InfraRed Imaging Spectrograph (IRIS) [1][2][3][4] for the Thirty Meter Telescope (TMT) is an imaging camera (imager) and integral field spectrograph (IFS) operating in the near infrared 0.8 µm -2.4 µm wavelength range. The imager will sample the diffraction limit of TMT's 30 meter aperture and will provide a spatial plate scale of 4 miliarcseconds (mas) per spatial pixel over a 34 x 34 arcsecond field of view, distributed over four Teledyne Hawaii-4RG-10µm detectors.…”

The infrared imaging spectrograph (IRIS) for TMT: overview of innovative science programs

“…The data reduction pipeline for the IFS will need to address the unique spectral extraction techniques for both the lenslet and slicer based spectrograph. 8 The imager data reduction pipeline will include typical reduction procedures of sky and dark subtraction, correction of detector artifacts (e.g., crosstalk), correction of cosmic rays, flat fielding, field distortion correction, flux calibration, PSF calibration, and advanced shift and add mosaicking routines. The expected challenges for this pipeline will likely be addressing new artifacts and anomalies with the newest Hawaii-4RG detectors and PSF calibrations.…”

“…IRIS (InfraRed Imaging Spectrograph) is one such revolutionary instrument being designed to sample the diffraction limit obtained from the multi-conjugate adaptive optics system, NFIRAOS 6 , on the future Thirty Meter Telescope (TMT 7 ). IRIS will house a dedicated near-infrared (0.845 -2.4 µm) imager and integral field spectrograph (IFS), as described by Moore et al [8], this conference. Both imager and IFS will offer unprecedented angular resolution, sampled with the imager at 4 mas/pixel with a total field of view † of 16.4ʹ′ʹ′ × 16.4ʹ′ʹ′ and the IFS with four spatial scales spanning 4 -50 mas/spaxel with a range of field of views from 0.064ʹ′ʹ′ × 0.51ʹ′ʹ′ to 4.4ʹ′ʹ′ × 2.25ʹ′ʹ′.…”

Diffraction limited integral field spectrographs for large telescopes

“…All of the lenslet-based spectrographs rely on the ground-breaking designs from Roland Bacon of spectrographs such as the optical Tiger Instrument [16] . For the Thirty Meter Telescope [17] one of the first light instruments is also a diffraction limited integral field spectrograph called IRIS [18,19] , which will use a lenslet array for the two finest plate scales and a slicer for the two coarsest scales.…”