GYES, a multifibre spectrograph for the CFHT

TL;DR

GYES is a proposed multifibre spectrograph for CFHT designed to complement Gaia by providing high-resolution spectra for stars, enabling precise chemical and velocity measurements in the northern sky.

Contribution

This paper presents a feasibility study for GYES, a high multiplex, high-resolution spectrograph for CFHT, leveraging previous experience and aiming to enhance stellar observations.

Findings

Feasibility of a 500-fibre spectrograph over 1-degree field

Resolution range of 15000 to 30000 for accurate stellar data

Capability to measure chemical abundances and radial velocities

Abstract

We have chosen the name of GYES, one of the mythological giants with one hundred arms, offspring of Gaia and Uranus, for our instrument study of a multifibre spectrograph for the prime focus of the Canada-France-Hawaii Telescope. Such an instrument could provide an excellent ground-based complement for the Gaia mission and a northern complement to the HERMES project on the AAT. The CFHT is well known for providing a stable prime focus environment, with a large field of view, which has hosted several imaging instruments, but has never hosted a multifibre spectrograph. Building upon the experience gained at GEPI with FLAMES-Giraffe and X-Shooter, we are investigating the feasibility of a high multiplex spectrograph (about 500 fibres) over a field of view 1 degree in diameter. We are investigating an instrument with resolution in the range 15000 to 30000, which should provide accurate chemical abundances for stars down to 16th magnitude and radial velocities, accurate to 1 km/s for fainter stars. The study is led by GEPI-Observatoire de Paris with a contribution from Oxford for the study of the positioner. The financing for the study comes from INSU CSAA and Observatoire de Paris. The conceptual study will be delivered to CFHT for review by October 1st 2010.