JWST MIRI flight performance: Imaging

¹ UK Astronomy Technology Centre, Royal Observatory Edinburgh, Blackford Hill, Edinburgh EH9 3HJ, UK
e-mail: daniel.dicken@stfc.ac.uk
² European Space Agency, at Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
³ Steward Observatory, University of Arizona, Tucson, AZ 85721, USA
⁴ Centro de Astrobiología (CAB), CSIC-INTA, Carretera de Ajalvir km 4, Torrejón de Ardoz, 28850 Madrid, Spain
⁵ Sorbonne Université, CNRS, UMR 7095, Institut d’Astrophysique de Paris, 98bis bd Arago, 75014 Paris, France
⁶ Institut Universitaire de France, Ministère de l'Enseignement Supérieur et de la Recherche, 1 rue Descartes, 75231 Paris Cedex 05, France
⁷ AURA for the European Space Agency (ESA), Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
⁸ INAF – Osservatorio Astronomico di Padova, Vicolo dell'Osservatorio 5, Padova, 35122, Italy
⁹ Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
¹⁰ Sterrenkundig Observatorium, Universiteit Gent, Gent, Belgium
¹¹ Université Paris-Saclay, CEA, IRFU, 91191 Gif-sur-Yvette, France
¹² School of Cosmic Physics, Dublin Institute for Advanced Studies, 31 Fitzwilliam Place, Dublin 2, Ireland
¹³ Princeton University, 4 Ivy Ln, Princeton, NJ 08544, USA
¹⁴ LERMA, Observatoire de Paris, Université PSL, Sorbonne Université, CNRS, Paris, France
¹⁵ Max Planck Institute for Astronomy, Kónigstuhl 17, 69117 Heidelberg, Germany
¹⁶ Institute for Particle Physics and Astrophysics, ETH Zurich, Wolfgang-Paulistr. 27, 8093 Zurich, Switzerland
¹⁷ Telespazio UK for the European Space Agency (ESA), ESAC, Camino Bajo del Castillo s/n, 28692 Villanueva de la Cañada, Spain
¹⁸ Department of Physics and Astronomy, University of North Carolina, Chapel Hill, NC 27599-3255, USA

Received: 1 February 2024
Accepted: 25 March 2024

Abstract

The Mid-Infrared Instrument (MIRI) aboard the James Webb Space Telescope (JWST) provides the observatory with a huge advance in mid-infrared imaging and spectroscopy covering the wavelength range of 5–28 µm. This paper describes the performance and characteristics of the MIRI imager as understood during observatory commissioning activities, and through its first year of science operations. We discuss the measurements and results of the imager’s point spread function, flux calibration, background, distortion and flat fields as well as results pertaining to best observing practices for MIRI imaging, and discuss known imaging artefacts that may be seen during or after data processing. Overall, we show that the MIRI imager has met or exceeded all its pre-flight requirements, and we expect it to make a significant contribution to mid-infrared science for the astronomy community for years to come.