Calibration unit for the near-infrared spectropolarimeter SPIRou

TL;DR

This paper details the design and implementation of a calibration unit for SPIRou, a near-infrared spectropolarimeter aimed at detecting Earth-like exoplanets and studying stellar magnetic fields, emphasizing unique calibration challenges and solutions.

Contribution

It introduces the specific calibration techniques, architecture, and design of the calibration unit tailored for SPIRou's near-infrared capabilities, differing from existing spectrographs.

Findings

Calibration unit achieves 1 m/s radial velocity precision

Design addresses near-infrared specific calibration challenges

Successful integration of calibration system with SPIRou instrument

Abstract

SPIRou is a near-infrared spectropolarimeter and high precision radial velocity instrument, to be implemented at CFHT in end 2017. It focuses on the search for Earth-like planets around M dwarfs and on the study of stellar and planetary formation in the presence of stellar magnetic field. The calibration unit and the radial-velocity reference module are essential to the short- and long-term precision (1 m/s). We highlight the specificities in the calibration techniques compared to the spectrographs HARPS (at LaSilla, ESO) or SOPHIE (at OHP, France) due to the near-infrared wavelengths, the CMOS detectors, and the instrument design. We also describe the calibration unit architecture, design and production.