Overview and status of the front-end instrument (FEI) Keck/HISPEC, the diffraction-limited y-K band spectrograph for exoplanet characterization

Le résumé fourni par la source

The High-Resolution Infrared Spectrograph for Exoplanet Characterization (HISPEC) is a new instrument for the W. M. Keck Observatory that enables R∼100,000 spectroscopy simultaneously across the y, J, H, and K astronomical bands (0.98-2.5 μm). The front-end instrument steers the adaptive optics corrected beam delivered by Keck to single-mode fibers used to route the light to the spectrographs. The basic architecture of the front-end instrument leverages from the design from the Keck Planet Imager and Characterizer where a tracking camera is used to monitor the location of the target and send commands to a tip/tilt mirror mounted in a pupil plane, which aligns the beam with the fiber in the downstream focal plane. The system will have an atmospheric dispersion corrector to minimize chromatic smearing of the PSF, phase induced amplitude apodization optics to mitigate coupling limitations imposed by the pupil geometry, and vortex masks to enable vortex fiber nulling. The front-end instrument will utilize a Teledyne H2RG for tracking allowing for the ability to guide on targets as faint as 15th magnitude and for tip/tilt control up to 500 Hz on brighter targets. In this paper we provide an overview of the detailed design of the front-end instrument and elucidate the design choices driven by de-risking exercises. We will describe our plan to utilize the J-H gap for tracking which will allow for uninterrupted science for a large population of targets. We present how the front-end instrument will be integrated into the Keck adaptive optics bench to allow for easy removal and cable management. Finally, we provide an update on the project status and the timeline for the sub-system.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.