Research
Galaxy Interactions and Mergers:
Galaxy interactions and mergers can be a site of particular interest when discussing galaxy evolution. Galaxy interactions and mergers can trigger numerous processes, such as the enhancement of star formation, fueling of active galactic nuclei (AGN) activity, and triggering of quasars. However, despite its importantance, a definitive conclusion on the relative role of mergers in these processes is difficult to make. One reason for such difficulty is the elusiveness of making a complete and precise catalogue of interacting galaxies.
In my research, I not only search for an identification method for interacting galaxies, but conduct studies using the identified galaxies, in numerous galaxy surveys.
Kinematic Approach
Kiyoaki Christopher Omori & Tsutomu T. Takeuchi, “The bimodality in the mass-metallicity relation in SDSS MaNGA galaxy pairs”, Astronomy and Astrophysics, Article Number 145, Volume 660, April 2022. https://doi.org/10.1051/0004-6361/202142858
Kiyoaki Christopher Omori & Tsutomu T. Takeuchi, “Spatially resolved properties of galaxies with a kinematically distinct core”, Astronomy and Astrophysics, Article Number 181, Volume 647, March 2021. https://doi.org/10.1051/0004-6361/202038244
Galaxy interactions and mergers can create disturbances in the stellar and gasesous motions (kinematics) of galaxies. Using the spatially resolved kinematic and imaging data in the SDSS-MaNGA survey, we identify interacting galaxies in Work 1, and galaxies with a kinematically distinct core (KDC) in Work 2.
In Work 1, we study the mass-metallicity relation (MZR) of mergers identified using this method.
In Work 2, we study the stellar populations of galaxies with KDCs, and discuss the possible role of mergers in the formation of such cores.
Deep Represenation Learning Approach
Omori et al. in prep...
We hope to publish this deep representation learning based approach of merger identification in Subaru HSC-SSP within the first half of 2023.