The Mid-Infrared Instrument for the James Webb Space Telescope, V: Predicted Performance of the MIRI Coronagraphs

TL;DR

This paper details the predicted performance and operational modes of the MIRI coronagraphs on the James Webb Space Telescope, including testing results and simulated observations for various astronomical targets.

Contribution

It provides the first comprehensive performance estimates and operational guidelines for MIRI's coronagraphs based on cryo-vacuum testing and simulations.

Findings

High contrast imaging capabilities demonstrated

Performance estimates align with laboratory measurements

Simulated observations illustrate potential scientific applications

Abstract

The imaging channel on the Mid-Infrared Instrument (MIRI) is equipped with four coronagraphs that provide high contrast imaging capabilities for studying faint point sources and extended emission that would otherwise be overwhelmed by a bright point-source in its vicinity. Such bright sources might include stars that are orbited by exoplanets and circumstellar material, mass-loss envelopes around post-main-sequence stars, the near-nuclear environments in active galaxies, and the host galaxies of distant quasars. This paper describes the coronagraphic observing modes of MIRI, as well as performance estimates based on measurements of the MIRI flight model during cryo-vacuum testing. A brief outline of coronagraphic operations is also provided. Finally, simulated MIRI coronagraphic observations of a few astronomical targets are presented for illustration.