The Astrophysical Journal (Jan 2023)
Identifying Galaxy Mergers in Simulated CEERS NIRCam Images Using Random Forests
- Caitlin Rose,
- Jeyhan S. Kartaltepe,
- Gregory F. Snyder,
- Vicente Rodriguez-Gomez,
- L. Y. Aaron Yung,
- Pablo Arrabal Haro,
- Micaela B. Bagley,
- Antonello Calabró,
- Nikko J. Cleri,
- M. C. Cooper,
- Luca Costantin,
- Darren Croton,
- Mark Dickinson,
- Steven L. Finkelstein,
- Boris Häußler,
- Benne W. Holwerda,
- Anton M. Koekemoer,
- Peter Kurczynski,
- Ray A. Lucas,
- Kameswara Bharadwaj Mantha,
- Casey Papovich,
- Pablo G. Pérez-González,
- Nor Pirzkal,
- Rachel S. Somerville,
- Amber N. Straughn,
- Sandro Tacchella
Affiliations
- Caitlin Rose
- ORCiD
- Laboratory for Multiwavelength Astrophysics , School of Physics and Astronomy, Rochester Institute of Technology, 84 Lomb Memorial Drive, Rochester, NY 14623, USA ; [email protected]
- Jeyhan S. Kartaltepe
- ORCiD
- Laboratory for Multiwavelength Astrophysics , School of Physics and Astronomy, Rochester Institute of Technology, 84 Lomb Memorial Drive, Rochester, NY 14623, USA ; [email protected]
- Gregory F. Snyder
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Dr., Baltimore, MD 21218, USA
- Vicente Rodriguez-Gomez
- ORCiD
- Department of Physics and Astronomy, Johns Hopkins University , Baltimore, MD 21218, USA; Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México , Apdo. Postal 72-3, 58089 Morelia, Mexico
- L. Y. Aaron Yung
- ORCiD
- Astrophysics Science Division, NASA Goddard Space Flight Center , 8800 Greenbelt Rd., Greenbelt, MD 20771, USA
- Pablo Arrabal Haro
- ORCiD
- NSF’s National Optical-Infrared Astronomy Research Laboratory , 950 N. Cherry Ave., Tucson, AZ 85719, USA
- Micaela B. Bagley
- ORCiD
- Department of Astronomy, The University of Texas at Austin , Austin, TX, USA
- Antonello Calabró
- ORCiD
- INAF - Osservatorio Astronomico di Roma , via di Frascati 33, 00078 Monte Porzio Catone, Italy
- Nikko J. Cleri
- ORCiD
- Department of Physics and Astronomy, Texas A&M University , College Station, TX 77843-4242 USA; George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University , College Station, TX 77843-4242 USA
- M. C. Cooper
- ORCiD
- Department of Physics & Astronomy, University of California , Irvine, 4129 Reines Hall, Irvine, CA 92697, USA
- Luca Costantin
- ORCiD
- Centro de Astrobiología (CSIC-INTA) , Ctra de Ajalvir km 4, Torrejón de Ardoz, E-28850, Madrid, Spain
- Darren Croton
- ORCiD
- Centre for Astrophysics & Supercomputing, Swinburne University of Technology , Hawthorn, VIC 3122, Australia; ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D) , Australia
- Mark Dickinson
- ORCiD
- NSF’s National Optical-Infrared Astronomy Research Laboratory , 950 N. Cherry Ave., Tucson, AZ 85719, USA
- Steven L. Finkelstein
- ORCiD
- Department of Astronomy, The University of Texas at Austin , Austin, TX, USA
- Boris Häußler
- ORCiD
- European Southern Observatory , Alonso de Cordova 3107, Casilla 19001, Santiago, Chile
- Benne W. Holwerda
- ORCiD
- Physics & Astronomy Department, University of Louisville , Louisville, KY 40292, USA
- Anton M. Koekemoer
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Dr., Baltimore, MD 21218, USA
- Peter Kurczynski
- ORCiD
- Observational Cosmology Laboratory (Code 665), NASA Goddard Space Flight Center , Greenbelt, MD 20771, USA
- Ray A. Lucas
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Dr., Baltimore, MD 21218, USA
- Kameswara Bharadwaj Mantha
- Minnesota Institute for Astrophysics, University of Minnesota , 116 Church St. SE, Minneapolis, MN, 55455, USA
- Casey Papovich
- ORCiD
- Department of Physics and Astronomy, Texas A&M University , College Station, TX 77843-4242 USA; George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University , College Station, TX 77843-4242 USA
- Pablo G. Pérez-González
- ORCiD
- Centro de Astrobiología (CSIC-INTA) , Ctra de Ajalvir km 4, Torrejón de Ardoz, E-28850, Madrid, Spain
- Nor Pirzkal
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Dr., Baltimore, MD 21218, USA
- Rachel S. Somerville
- ORCiD
- Center for Computational Astrophysics, Flatiron Institute , 162 5th Avenue, New York, NY, 10010, USA
- Amber N. Straughn
- ORCiD
- Astrophysics Science Division, NASA Goddard Space Flight Center , 8800 Greenbelt Rd., Greenbelt, MD 20771, USA
- Sandro Tacchella
- ORCiD
- Kavli Institute for Cosmology, University of Cambridge , Madingley Road, Cambridge, CB3 0HA, UK; Cavendish Laboratory, University of Cambridge , 19 JJ Thomson Avenue, Cambridge, CB3 0HE, UK
- DOI
- https://doi.org/10.3847/1538-4357/ac9f10
- Journal volume & issue
-
Vol. 942,
no. 1
p. 54
Abstract
Identifying merging galaxies is an important—but difficult—step in galaxy evolution studies. We present random forest (RF) 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 and nearly noiseless observations, (b) measuring morphological parameters from these images, and (c) constructing and training the RFs using the merger history information for the simulated galaxies available from IllustrisTNG. The RFs 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 RF classifications match with theoretical Illustris predictions but are underestimated by a factor of ∼0.5.
Keywords
