Exact JWST/NIRCam PSFs for accurate decompositions

Determine the exact point spread functions (PSFs) of JWST/NIRCam across fields, filters, and relevant observational conditions to enable optimal configuration choices for PSF reconstruction and minimize biases in AGN–host galaxy decompositions.

Background

Accurate AGN–host decomposition critically depends on the fidelity of the PSF. The paper compares empirical modeling (PSFEx) and x^2-based stacking methods, noting differences in PSF width and ellipticity that propagate into morphological and photometric inferences.

Selecting optimal PSFEx configurations or stacking strategies requires knowledge of the true PSF, which is currently unavailable, complicating robust decomposition for large surveys.