Study of Satellite Plane Structure Characteristics Based on TNG50 Simulations: A Comparative Analysis from Plane to Non-Plane Structures

Abstract: In recent years, multiple plane structures of satellite galaxies have been identified in the nearby universe, although their formation mechanisms remain unclear. In this work, we employ the TNG50-1 numerical simulation to classify satellite systems into plane and non-plane structures, based on their geometric and dynamical properties. We focus on comparing the characteristics of these plane and non-plane structures. The plane structures in TNG50-1 exhibit a mean height of 5.24 kpc, with most of them found in galaxy groups with intermediate halo virial masses within the narrow range of $10^{11.5}$ to $10^{12.5}$ $M_\odot$. Statistical analyses reveal that plane structures of satellite galaxies constitute approximately 11.30% in TNG50-1, with this proportion increasing to 27.11% in TNG100-1, aligning closely with previous observations. Additionally, central galaxies in clusters and groups hosting co-rotating plane structures are intermediate massive and slightly metal-poorer than those in non-plane structures. Significant difference are found between in-plane and out-of-plane satellite galaxies, suggesting that in-plane satellites exhibit slightly longer formation times, and more active interstellar matter cycles. The satellites within these plane structures in TNG50-1 exhibit similar radial distributions with observations, but are fainter and more massive than those in observational plane structures, due to the over- or under-estimation of galaxy properties in simulations. Our analysis also shows that the satellite plane structures might be effected by some low- or high-mass galaxies temporarily entered the plane structures due to the gravitational potential of the clusters and groups after the plane structures had formed.