The Infrared Imaging Spectrograph (IRIS) for TMT: Instrument Overview

TL;DR

The IRIS instrument for TMT is a highly advanced infrared spectrograph and camera designed to achieve diffraction-limited imaging and spectroscopy at the 30-meter telescope, enabling detailed studies of distant and complex astrophysical objects.

Contribution

This paper provides the first comprehensive overview of IRIS's innovative design features and capabilities for high-resolution infrared astronomy at TMT.

Findings

Design achieves <30 nm wavefront error

Spectral resolution of 4000 with 4 mas sampling

Integration of lenslet and slicer integral field units

Abstract

We present an overview of the design of IRIS, an infrared (0.85 - 2.5 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 aperture. 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.