Euclid Near-Infrared Imaging Reduction Pipeline – Cosmic Ray Rejection on Multiple Frames

Abstract

Euclid is an ESA mission to map the geometry of the dark Universe. The mission will investigate the distance-redshift relationship and the evolution of cosmic structures by measuring shapes and redshifts of galaxies and clusters of galaxies out to redshifts ~2, or equivalently to a look-back time of 10 billion years. In this way, Euclid will cover the entire period over which dark energy played a significant role in accelerating the expansion. For a more detailed description of the goal of this mission, the structure of the ground segment and the Organization Units (OUs), see document [RD10]. The module described in this document is a Work-Package (WP) of the OU- Near InfraRed imaging data (NIR) pipeline. OU-NIR is the Organitation Unit dedicated to the reduction and management of Near InfraRed Spectrometer and Photometer (NISP) photometer data. The NIR Science Pipeline is composed by different WPs that deal to acquire row data, clean the input data by removing observational and instrumental effects, and create the images with astrometry and the relative catalogs. It's possible to divide science Pipeline in some main steps: 1. Init - (data initialization) 2. Pre-reduction [Bad pixel masking - Persistence correction] (in common with OU- SIR Pipeline) 3. Pre-processing/1 [Ghost and scattered light - Flat Field Corr.] 4. Pre-processing/2 [Super Flat Corr. and Illumination Corr.] 5. Astrometry [Relative and absolute Astrometry Corr.] 6. Photometry [Relative Photometry Corr.] 7. Resampling and Stacking 8. Catalogues and transients The WP for Cosmic Ray rejection on multiple frame (WP-6200 NIR_CrRejectionMultiFrame) is describe in this document.