MICADO Data Reduction Library Design for PSF Reconstruction Application

Abstract

MICADO is the Multi-Adaptive Optics (AO) Imaging Camera for Deep Observations. It will equip the European Southern Observatory (ESO) Extremely Large Telescope (ELT) with a first light capability for diffraction limited imaging and long-slit spectroscopy at near-infrared wavelengths. MICADO (MCD) is a workhorse instrument for the E-ELT. While its primary focus is AO-assisted imaging, it provides a high level of flexibility for modes that are not necessarily offered by other E-ELT instruments, and that will lead to observations with a major scientific impact. The instrument will work with a multi-conjugate laser guide star adaptive optics system (MCAO, developed by the MAORY consortium) as well as a single-conjugate natural guide star adaptive optics system (SCAO, developed jointly by the MICADO and MAORY consortia). It will interface to the MAORY warm optical relay that re-images the telescope focus. In this configuration, both MCAO and SCAO are available. If required for an initial phase, MICADO will also be able to operate with just the SCAO system in a “stand-alone” mode, using a simpler optical relay that interfaces directly to the telescope. MICADO has four observing modes producing data: Standard Imaging, Astrometric Imaging, High-contrast Imaging, and Spectroscopy. Each observing mode can optionally be operated in a configuration that gathers the data (Wave Front Sensing (WFS) images and telemetry) required for Point Spread Function (PSF) Reconstruction (PSF-R). The PSF Reconstruction (PSF-R) Team of MICADO will develop, for the first time within all ESO telescopes, a software service devoted to the reconstruction of the PSF. The PSF-R Team will build up the tools and architecture needed to develop and test the PSF-R Application for MICADO, when the instrument will be mounted on the bench (at PAE) and later on the ELT site (at PAC). The coupling with ELT telescope is fundamental for the definition of the shape of the PSF and implies a large refinement work to be performed on data collected on the sky. Since the MICADO PSF-R tool is the first experiment of its kind using (for SCAO) pyramid WFS telemetry data, the PSF-R Team opted for over-specifying the list of possible inputs and effects at FDR: it will be assessed on later phases whether the error sources are marginal or not. Preliminary analysis of the main effects has already been started. The PSF-R tools is not recommended for the High-contrast imaging mode, since this mode focuses instead on canceling the PSF using peculiar observational and instrumental techniques (i.e. Angular Differential Imaging and Coronography). The reconstructed PSF in High-contrast imaging mode can be used e.g. in order to characterise a detected exoplanet, but not for subtracting the primary bright star. Moreover, the PSF-R Applications will not work for the seeing enhancer and seeing limited (No-AO) modes. In the case of spatially resolved AO reference guide objects, i.e. satellite in non-sidereal imaging mode, or observations in tracking field mode, the PSF-R will suffer from larger errors and it is not recommended.