Details

Autor(en) / Beteiligte

• Hobson, M. J.
• Bouchy, F.
• Cook, N. J.
• Artigau, E.
• Moutou, C.
• Boisse, I.
• Lovis, C.
• Carmona, A.
• Delfosse, X.
• Donati, J.-F.

Titel

The SPIRou wavelength calibration for precise radial velocities in the near infrared

Ist Teil von

• Astronomy and astrophysics (Berlin), 2021-04, Vol.648, p.A48

Ort / Verlag

EDP Sciences

Erscheinungsjahr

2021

Link zum Volltext

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• Aims. SPIRou is a near-infrared (nIR) spectropolarimeter at the CFHT, covering the YJHK nIR spectral bands (980−2350 nm). We describe the development and current status of the SPIRou wavelength calibration in order to obtain precise radial velocities (RVs) in the nIR. Methods. We make use of a UNe hollow-cathode lamp and a Fabry-Pérot étalon to calibrate the pixel-wavelength correspondence for SPIRou. Different methods are developed for identifying the hollow-cathode lines, for calibrating the wavelength dependence of the Fabry-Pérot cavity width, and for combining the two calibrators. Results. The hollow-cathode spectra alone do not provide a sufficiently accurate wavelength solution to meet the design requirements of an internal error of < 0.45 m s −1 , for an overall RV precision of 1 m s −1 . However, the combination with the Fabry-Pérot spectra allows for significant improvements, leading to an internal error of ∼0.15 m s −1 . We examine the inter-night stability, intra-night stability, and impact on the stellar RVs of the wavelength solution.