A new infrared Fabry-Pérot-based radial-velocity-reference module for the SPIRou radial-velocity spectrograph

Abstract

The field of exoplanet research is moving towards the detection and characterization of habitable planets. These exo-Earths can be easily found around low-mass stars by using either photometric transit or radial-velocity (RV) techniques. In the latter case the gain is twofold because the signal induced by the planet of a given mass is higher due to the more favourable planet-star mass ratio and because the habitable zone lies closer to the star. However, late-type stars emit mainly in the infrared (IR) wavelength range, which calls for IR instruments. SPIRou is a stable RV IR spectrograph addressing these ambitious scientific objectives. As with any other spectrograph, calibration and drift monitoring is fundamental to achieve high precision. Our goal was to build, test and finally operate a Fabry-Pérot-based RV-reference module able to provide the needed spectral information over the full wavelength range of SPIRou. We adapted the existing HARPS Fabry-Pérot calibrator for operation in the IR domain. After manufacturing and assembly, we characterized the FP RV-module in the laboratory. We measured finesse, transmittance, and spectral flux of the system. The measured finesse value of F=12.8 corresponds perfectly to the theoretical value. The total transmittance at peak is of the order of 0.5%, mainly limited by fibre-connectors and interfaces. Nevertheless, the provided flux is in line with the the requirements set by the SPIRou instrument. Once installed on SPIRou, we will test the full spectral characteristics and stability of the RV-reference module. The goal will be to prove that the line position and shape stability of all lines is better than 0.3 m s${}^{-1}$ between two calibration sequences (typically 24 hours), such that the RV-reference module can be used to monitor instrumental drifts.

13 pages, 21 figures, accepted on 30-01-2017 in section 13. Astronomical instrumentation of Astronomy and Astrophysics

References in corpus (5)

• Detecting Planets Around Very Low Mass Stars with the Radial Velocity Method
• Demonstration of On-Sky Calibration of Astronomical Spectra using a 25 GHz near-IR Laser Frequency Comb
• The effect of M dwarf starspot activity on low-mass planet detection thresholds
• Stabilizing a Fabry-Perot etalon to 3 cm/s for spectrograph calibration
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• The CORALIE survey for southern extrasolar planets XIX. Brown dwarfs and stellar companions unveiled by radial velocity and astrometry
• TESS discovery of a sub-Neptune orbiting a mid-M dwarf TOI-2136
• EPIC 201498078b: A low density Super Neptune on an eccentric orbit
• Probing atmospheric escape through metastable He I triplet lines in 15 exoplanets observed with SPIRou
• Instrument Simulator and Data Reduction Pipeline for the iLocater Spectrograph
• Effect of near-field distribution on transmission characteristics of fiber-fed Fabry-Perot etalons
• Discovery of a cold giant planet and mass measurement of a hot super-Earth in the multi-planetary system WASP-132
• Developement of a stabilized Fabry-Perot etalon based calibrator for Hanle Echelle Spectrograph (HESP)
• First on-sky results of a FIOS prototype, a Fabry Perot Based Instrument for Oxygen Searches
• Exploring stellar activity in a sample of active M dwarfs