AGN--Host Galaxy Image Decomposition with JWST
Callum Dewsnap (1), Pauline Barmby (1, 2), Sarah C. Gallagher (1, 2) ((1) Department of Physics & Astronomy, The University of Western Ontario, (2) Institute for Earth & Space Exploration, The University of Western University)

TL;DR
This study evaluates how different PSF models and fitting software affect measurements of AGN host galaxy properties using JWST imaging, revealing limitations in current modeling approaches.
Contribution
It systematically compares PSF modeling and fitting software for AGN-host decomposition, highlighting inconsistencies and limitations in morphological parameter recovery.
Findings
PSFEx models fail to match typical point source profiles
Galfit and AstroPhot yield different host galaxy parameters
Sérsic index and radius are covariant and not well constrained
Abstract
The ability to disentangle the light of an AGN from its host galaxy is strongly dependent on the spatial resolution and depth of the imaging. As the capabilities of imaging systems improve with time, confirming that our standard techniques adequately model the increasingly complex structures unveiled is essential. With JWST providing unprecedented image quality, we can test how measurements of galaxy morphology vary with the choice of point-spread function (PSF) and fitting software. We perform two-component S\'ersic+PSF fits of the surface brightness profiles of 87 X-ray AGNs from the CEERS survey. We create model PSFs for NIRCam F115W imaging using both photutils and PSFEx. We find that PSFEx models consistently fail to match the radial profile of typical point sources within our sample. We then perform AGN--host decompositions on each source by creating S\'ersic+PSF…
Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.
Taxonomy
TopicsGalaxies: Formation, Evolution, Phenomena · Astronomy and Astrophysical Research · Space Technology and Applications
