17-21 March 2019
Sunstar Hotel, Grindelwald, Switzerland
Europe/Zurich timezone

Calibrating SPIRou in Wavelength

Not scheduled
Sunstar Hotel, Grindelwald, Switzerland

Sunstar Hotel, Grindelwald, Switzerland

Dorfstrasse 168, 3818 Grindelwald Switzerland
Poster Instrument and calibration challenges


Melissa Hobson (Laboratoire d'Astrophysique de Marseille)


Abstract: In order to measure stellar radial velocities at high precision, an accurate wavelength solution is of paramount importance. To achieve such a solution, hollow-cathode (HC) lamps have frequently been used (e.g. on HARPS, SOPHIE). By identifying and cross-matching their spectral lines with very precise catalogues, a pixel-wavelength correlation can be generated. However, these spectral lines are irregularly spaced and of highly varying intensity, and the resulting wavelength solutions are accurate only to the meter-per-second level.

Therefore, to improve the wavelength calibration, different solutions have been sought. One is the use of a Fabry-Pérot (FP) etalon; this provides a multitude of lines which are evenly spaced but whose wavelength is not accurately known. Combined with a hollow-cathode lamp to supply an absolute wavelength identification of the FP lines, it serves to better constrain the wavelength solution. Such a HC-FP combination is used by e.g. CARMENES, ESPRESSO.

In this contribution, we will present the development of the SPIRou wavelength solution. SPIRou makes use of a UNe hollow-cathode lamp, with a plethora of catalogued rays in the near infrared, and a Fabry-Pérot etalon which generates lines covering the whole domain. We describe the different approaches tested, challenges encountered and lessons learned.

Primary authors

Melissa Hobson (Laboratoire d'Astrophysique de Marseille) Prof. Isabelle Boisse (Aix Marseille Univ, CNRS, CNES, LAM, Marseille, France) François Bouchy Dr Etienne Artigau (Institut de Recherche sur les Exoplanètes (IREx), Département de Physique, Université de Montréal,) Dr Neil Cook (Institut de Recherche sur les Exoplanètes (IREx), Département de Physique, Université de Montréal,) Dr Claire Moutou (Canada-France-Hawaii Telescope Corporation, 65-1238 Mamalahoa Hwy, Kamuela, HI 96743, USA) SPIRou team

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