14 September 2005 High contrast imaging with the JWST NIRCAM coronagraph
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Relative to ground-based telescopes, the James Webb Space Telescope (JWST) will have a substantial sensitivity advantage in the 2.2-5μm wavelength range where brown dwarfs and hot Jupiters are thought to have significant brightness enhancements. To facilitate high contrast imaging within this band, the Near-Infrared Camera (NIRCAM) will employ a Lyot coronagraph with an array of band-limited image-plane occulting spots. In this paper, we provide the science motivation for high contrast imaging with NIRCAM, comparing its expected performance to that of the Keck, Gemini and 30 m (TMT) telescopes equipped with Adaptive Optics systems of different capabilities. We then describe our design for the NIRCAM coronagraph that enables imaging over the entire sensitivity range of the instrument while providing significant operational flexibility. We describe the various design tradeoffs that were made in consideration of alignment and aberration sensitivities and present contrast performance in the presence of JWST's expected optical aberrations. Finally we show an example of a two-color image subtraction that can provide 10-5 companion sensitivity at sub-arcsecond separations.
© (2005) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Joseph J. Green, Charles Beichman, Scott A. Basinger, Scott Horner, Michael Meyer, David C. Redding, Marcia Rieke, John T. Trauger, "High contrast imaging with the JWST NIRCAM coronagraph", Proc. SPIE 5905, Techniques and Instrumentation for Detection of Exoplanets II, 59050L (14 September 2005); doi: 10.1117/12.619343; https://doi.org/10.1117/12.619343

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