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arXiv · 2404.04061

KRATOS: A large suite of N-body simulations to interpret the stellar kinematics of LMC-like discs

Ó. Jiménez-Arranz·S. Roca-Fàbrega·M. Romero-Gómez·X. Luri·M. Bernet·P. J. McMillan·L. Chemin
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Abstract

We present KRATOS, a comprehensive suite of 28 open access pure N-body simulations of isolated and interacting LMC-like galaxies, to study the formation of substructures in their disc after the interaction with an SMC-mass galaxy. The primary objective of this paper is to provide theoretical models that help interpreting the formation of general structures of an LMC-like galaxy under various tidal interaction scenarios. This is the first paper of a series that will be dedicated to the analysis of this complex interaction. Simulations are grouped in 11 sets of at most three configurations each containing: (1) a control model of an isolated LMC-like galaxy; (2) a model that contains the interaction with an SMC-mass galaxy, and; (3) the most realistic configuration where both an SMC-mass and MW-mass galaxies may interact with the LMC-like galaxy. In each simulation, we analyse the orbital history between the three galaxies and examine the morphological and kinematic features of the LMC-like disc galaxy throughout the interaction. This includes investigating the disc scale height and velocity maps. When a bar develops, our analysis involves characterising its strength, length, off-centeredness and pattern speed. The diverse outcomes found in the KRATOS simulations, including the presence of bars, warped discs, or various spiral arm shapes (along with the high spatial, temporal, and mass resolution used), demonstrate their capability to explore a range of LMC-like galaxy morphologies. Those directly correspond to distinct disc kinematic maps, making them well-suited for a first-order interpretation of the LMC's kinematic maps. From the simulations we note that tidal interactions can: boost the disc scale height; both destroy and create bars, and; naturally explain the off-center stellar bars. The bar length and pattern speed of long-lived bars are not appreciably altered by the interaction.

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Ó. Jiménez-Arranz, S. Roca-Fàbrega, M. Romero-Gómez, X. Luri, M. Bernet, P. J. McMillan, L. Chemin. 2024-04-05. KRATOS: A large suite of N-body simulations to interpret the stellar kinematics of LMC-like discs. https://arxiv.org/abs/2404.04061

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