Robust removal of MIRI PSF spikes around bright galaxy centers

Develop a robust method for removing JWST Mid-Infrared Instrument (MIRI) point-spread function diffraction spikes produced by bright nuclear sources (e.g., active galactic nuclei and compact star clusters) in PHANGS-JWST mosaics while preserving the underlying extended emission and avoiding oversubtraction artifacts.

Background

The PHANGS-JWST mosaics show prominent MIRI PSF spikes near bright galaxy centers that contaminate extended emission. Tests using WebbPSF-based subtraction tend to oversubtract, likely due to effects such as the brighter-fatter behavior and limitations in current PSF models. The authors indicate that a reliable correction remains to be developed, and analyses often mask these regions as a stopgap measure.