Identifying merging galaxies is an important - but difficult - step in galaxy evolution studies. We present random forest classifications of galaxy mergers from simulated JWST images based on various standard morphological parameters. We describe (a) constructing the simulated images from IllustrisTNG and the Santa Cruz SAM, and modifying them to mimic future CEERS observations as well as nearly noiseless observations, (b) measuring morphological parameters from these images, and (c) constructing and training the random forests using the merger history information for the simulated galaxies available from IllustrisTNG. The random forests correctly classify ∼60% of non-merging and merging galaxies across 0.5<z<4.0. Rest-frame asymmetry parameters appear more important for lower redshift merger classifications, while rest-frame bulge and clump parameters appear more important for higher redshift classifications. Adjusting the classification probability threshold does not improve the performance of the forests. Finally, the shape and slope of the resulting merger fraction and merger rate derived from the random forest classifications match with theoretical Illustris predictions, but are underestimated by a factor of ∼0.5.
@article{arxiv.2208.11164,
title = {Identifying Galaxy Mergers in Simulated CEERS NIRCam Images using Random Forests},
author = {Caitlin Rose and Jeyhan S. Kartaltepe and Gregory F. Snyder and Vicente Rodriguez-Gomez and L. Y. Aaron Yung and Pablo Arrabal Haro and Micaela B. Bagley and Antonello Calabrò and Nikko J. Cleri and M. C. Cooper and Luca Costantin and Darren Croton and Mark Dickinson and Steven L. Finkelstein and Boris Häußler and Benne W. Holwerda and Anton M. Koekemoer and Peter Kurczynski and Ray A. Lucas and Kameswara Bharadwaj Mantha and Casey Papovich and Pablo G. Pérez-González and Nor Pirzkal and Rachel S. Somerville and Amber N. Straughn and Sandro Tacchella},
journal= {arXiv preprint arXiv:2208.11164},
year = {2023}
}