PDRs4ALL XX. Spectral stitching of MIRI cubes

The MIRI Medium-Resolution Spectrometer (MRS) consists of four integral field units (IFU) and two wheels with three rotation settings producing four spectral channels and three spectral sub-channels. The twelve resulting spectral data cubes have different fields of view, spatial, and spectral resolutions.

The wavelength range of each cube partially overlaps with the neighboring bands, and the overlap regions typically show flux mismatches which have to be corrected by spectral stitching methods. Stitching methods aim to produce a single data cube incorporating the data of the individual sub-channels, which requires matching the spatial resolution and the flux discrepancies. We present Haute Couture, a novel stitching algorithm which uses non-negative matrix factorization (NMF) to perform a matrix completion, where the available MRS data cubes are treated as twelve sub-matrices of a larger incomplete matrix.