JWST MIRI flight performance: The Medium-Resolution Spectrometer

• DOI: 10.48550/arxiv.2303.13469
• Publication Date: 2023-01-01
• Authors: Ioannis Argyriou; Alistair Glasse; David R. Law; Á. Labiano; Javier Álvarez-Má...; Polychronis Patapis; Patrick Kavanagh; Danny Gasman; Michael Mueller; Kirsten L. Larson; B. Vandenbussche; Adrian M. Glauser; P. Royer; D. Dicken; Jake Harkett; Beth A. Sargent; Michael Engesser; Olivia Jones; Sarah Kendrew; A. Noriega‐Crespo; Bernhard R. Brandl; G. H. Rieke; Gillian Wright; David Lee; Martyn Wells
• Keywords: Spectral resolution

The Medium-Resolution Spectrometer (MRS) provides one of the four operating modes Mid-Infrared Instrument (MIRI) on board James Webb Space Telescope (JWST). MRS is an integral field spectrometer, measuring spatial and spectral distributions light across 5-28 $μm$ wavelength range with a resolving power between 3700-1300. We present MRS's optical, spectral, spectro-photometric performance, as achieved in flight, we report effects that limit instrument's ultimate sensitivity. flight performance has been quantified using observations stars, planetary nebulae, planets our Solar System. precision accuracy this calibration was checked against celestial calibrators well-known flux levels features. find geometric distortion solution relative to commanded position 8 mas at 5 23 28 $μm$. accurate within 9 km/sec 27 uncertainty absolute estimated 5.6 +- 0.7 %. MIRI pipeline able suppress amplitude fringes below 1.5 % for both extended point sources entire range. spread function (PSF) 60 broader than diffraction along its long axis 15 found be better prelaunch expectations. most subscribed observing JWST yielding many high-profile publications. It currently humanity's powerful instrument mid-infrared spectra expected continue such years come.