Description
The Local Group (LG), as a gravitationally bound system of the Milky Way and Andromeda, as well as their satellites, is a cornerstone of near-field cosmology. However, its utility as a cosmological probe requires understanding how it is related to the cosmic web. Using the ABACUSSUMMIT simulation, we identify LG analogues and quantify their environmental dependence. We find that the coupling energy of LG-analogue systems strongly correlates with large-scale overdensity, revealing a secondary bias effect. Crucially, we demonstrate that the LG-analogues are aligned to the anisotropic part of the cosmic web, and the alignment pattern is dependent on the coupling energy of the system. Our results underscore the role of non-local environmental effects in shaping LG-like systems and argue against treating the LG as an isolated system. Instead, we advocate for integrating the large-scale cosmic web into studies of LG analogues.
