The anisotropic distribution of the satellites in Milky-Way-like galaxy systems
| Autor: | Zhao, Xinghai, Mathews, Grant J., Phillips, Lara Arielle, Tang, Guobao |
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| Jazyk: | angličtina |
| Rok vydání: | 2023 |
| Předmět: | |
| Popis: | Aim. The satellite systems of Milky-Way-like galaxies offer a useful means by which to study the galaxy formation process in the cosmological context. It has been suggested that the currently observed anisotropic distribution of the satellites in such galaxy systems is inconsistent with the concordant $\Lambda CDM$ cosmology model on the galactic scale if the observed satellites are random samples of the dark matter (DM) sub-halos that are nearly isotropically distributed around the central galaxy. Here we examine such systems in the context of a simulation of the Local Group. Methods. We use high resolution hydrodynamical simulations of the formation and evolution of Milky-Way-like galaxy systems to investigate the spatial distribution of the luminous satellites and DM sub-halos around the central galaxy. Results. We find that the satellites and DM sub-halos are indeed anisotropically distributed with a direction roughly along the local DM filament. The observed alignment of the satellites in these systems is likely the result of preferred accretion along the local DM filaments in the galaxy formation process. For the dynamical properties of the satellites, we find that the direction of the angular momentum vector of the whole satellite system is different from the normal direction of the fitted "disk of satellites" (DOS) and the normal direction of the velocity dispersion of the system. Hence, the fitted DOS appears to be infalling and is not rotationally supported in this study. Comment: 12 pages, 13 figures |
| Databáze: | OpenAIRE |
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