Conceptual Design of the Coronagraphic High Angular Resolution Imaging Spectrograph (CHARIS) for the Subaru Telescope

TL;DR

The paper presents the conceptual design of CHARIS, a cryogenic integral field spectrograph for the Subaru telescope, enabling high-contrast imaging and spectroscopy of exoplanets in the near-infrared with multiple spectral resolutions.

Contribution

It introduces a novel lenslet-based IFS design for CHARIS, tailored for exoplanet imaging with adaptive optics and coronagraphs on the Subaru telescope.

Findings

Design specifications for CHARIS IFS detailed

Expected to achieve high contrast for exoplanet spectra

Operational modes with different spectral resolutions

Abstract

Recent developments in high-contrast imaging techniques now make possible both imaging and spectroscopy of planets around nearby stars. We present the conceptual design of the Coronagraphic High Angular Resolution Imaging Spectrograph (CHARIS), a lenslet-based, cryogenic integral field spectrograph (IFS) for imaging exoplanets on the Subaru telescope. The IFS will provide spectral information for 140x140 spatial elements over a 1.75 arcsecs x 1.75 arcsecs field of view (FOV). CHARIS will operate in the near infrared (lambda = 0.9 - 2.5 microns) and provide a spectral resolution of R = 14, 33, and 65 in three separate observing modes. Taking advantage of the adaptive optics systems and advanced coronagraphs (AO188 and SCExAO) on the Subaru telescope, CHARIS will provide sufficient contrast to obtain spectra of young self-luminous Jupiter-mass exoplanets. CHARIS is in the early design phases and is projected to have first light by the end of 2015. We report here on the current conceptual design of CHARIS and the design challenges.