Performance of the Canada‐France‐Hawaii Telescope Adaptive Optics Bonnette

TLDR

The paper presents and discusses extensive commissioning results of PUEO, the CFHT adaptive optics adaptor. The authors analyze over 750 images across B–H wavelengths to characterize PUEO’s wavefront correction, reporting Strehl ratios, FWHM, and image quality improvements, and describe a user interface that automatically optimizes mode gains during observations. PUEO delivers diffraction‑limited images at H and K and sub‑0.1″ FWHM at J and I under median seeing, achieving significant gains down to B with guide stars as faint as R = 14, and even better performance with R = 17 guide stars in good conditions, as illustrated by several astronomical examples.

Abstract

Extensive results from the commissioning phase of PUEO, the adaptive optics instrument adaptor for the Canada‐France‐Hawaii Telescope (CFHT), are presented and discussed. Analyses of more than 750 images recorded with a CCD and a near‐IR camera on 16 nights in wavelengths from B to H are used to derive the properties of the compensated wavefront and images in a variety of conditions. The performance characteristics of the system are analyzed and presented in several ways, in terms of delivered Strehl ratios, full width half‐maxima (FWHM), and quantities describing the improvements of both. A qualitative description is given of how the properties of the corrected images result from the structure function of the compensated phase. Under median seeing conditions, PUEO delivers essentially diffraction‐limited images at H and K and images with FWHM ∼ 01 at J and I, and provides significant gains down to B, with guide stars as faint as R = 14. During good conditions, substantial gains were realized with guide stars as faint as R = 17. A simple user interface and software that automatically and continuously optimizes the mode gains during observations makes the operational efficiency extremely high. A few astronomical examples are briefly discussed.