Exploring Lenticular Galaxy Formation in Field Environments Using NewHorizon: Evidence for Counterrotating Gas Accretion as a Formation Channel

Han, Seongbong, Jang, J. K., Contini, Emanuele, Dubois, Yohan, Jeon, Seyoung, Kaviraj, Sugata, Kimm, Taysun, Kraljic, Katarina, Oh, Sree, Peirani, Sébastien, Pichon, Christophe and Yi, Sukyoung K. (2024) Exploring Lenticular Galaxy Formation in Field Environments Using NewHorizon: Evidence for Counterrotating Gas Accretion as a Formation Channel. The Astrophysical Journal, 977 (1): 116. pp. 1-14. ISSN 0004-637X

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The formation pathways of lenticular galaxies (S0s) in field environments remain a matter of debate. We utilize the cosmological hydrodynamic simulation, NewHorizon, to investigate the issue. We select two massive star formation quenched S0s as our main sample. By closely tracing their physical and morphological evolution, we identify two primary formation channels: mergers and counterrotating gas accretion. The former induces central gas inflow due to gravitational and hydrodynamic torques, triggering active central star formation, which quickly depletes the gas of the galaxy. Counterrotating gas accretion overall has a similar outcome but more exclusively through hydrodynamic collisions between the preexisting and newly accreted gas. Both channels lead to S0 morphology, with gas angular momentum cancellation being a crucial mechanism. These formation pathways quench star formation on a short timescale (

Item Type	Article
Additional information	© 2024. The Author(s). Published by the American Astronomical Society. This is an open access article distributed under the Creative Commons Attribution License, to view a copy of the license, see: https://creativecommons.org/licenses/by/4.0/
Keywords	galaxy dynamics, galaxy formation, galaxy evolution, galaxy quenching, galaxy mergers
Date Deposited	15 May 2025 15:46
Last Modified	31 May 2025 00:46