Calibration Unit Design for High-Resolution Infrared Spectrograph for Exoplanet Characterization (HISPEC)

Ben Sappey; Quinn Konopacky; Nemanja Jovanovic; Ashley Baker; Jerome Maire; Samuel Halverson; Dimitri Mawet; Jean-Baptiste Ruffio; Rob Bertz; Michael Fitzgerald; Charles Beichman; Garreth Ruane; Marc Kassis; Chris Johnson; Ken Magnone; HISPEC Team

arXiv · 2311.10239

Calibration Unit Design for High-Resolution Infrared Spectrograph for Exoplanet Characterization (HISPEC)

Ben Sappey·Quinn Konopacky·Nemanja Jovanovic·Ashley Baker·Jerome Maire·Samuel Halverson·Dimitri Mawet·Jean-Baptiste Ruffio·Rob Bertz·Michael Fitzgerald·Charles Beichman·Garreth Ruane·Marc Kassis·Chris Johnson·Ken Magnone·HISPEC Team

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Abstract

The latest generation of high-resolution spectrograph instruments on 10m-class telescopes continue to pursue challenging science cases. Consequently, ever more precise calibration methods are necessary to enable trail-blazing science methodology. We present the High-resolution Infrared SPectrograph for Exoplanet Characterization (HISPEC) Calibration Unit (CAL), designed to facilitate challenging science cases such as Doppler imaging of exoplanet atmospheres, precision radial velocity, and high-contrast high-resolution spectroscopy of nearby exoplanets. CAL builds upon the heritage from the pathfinder instrument Keck Planet Imager and Characterizer (KPIC) and utilizes four near-infrared (NIR) light sources encoded with wavelength information that are coupled into single-mode fibers. They can be used synchronously during science observations or asynchronously during daytime calibrations. A hollow cathode lamp (HCL) and a series of gas absorption cells provide absolute calibration from 0.98 {\mu}m to 2.5 {\mu}m. A laser frequency comb (LFC) provides stable, time-independent wavelength information during observation and CAL implements a lower finesse astro-etalon as a backup for the LFC. Design lessons from instrumentation like HISPEC will serve to inform the requirements for similar instruments for the ELTs in the future.

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Ben Sappey, Quinn Konopacky, Nemanja Jovanovic, Ashley Baker, Jerome Maire, Samuel Halverson, Dimitri Mawet, Jean-Baptiste Ruffio, Rob Bertz, Michael Fitzgerald, Charles Beichman, Garreth Ruane, Marc Kassis, Chris Johnson, Ken Magnone, HISPEC Team. 2023-11-17. Calibration Unit Design for High-Resolution Infrared Spectrograph for Exoplanet Characterization (HISPEC). https://arxiv.org/abs/2311.10239

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