A new method for tracing the cosmic web
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Wednesday 10th
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A new method for tracing the cosmic web
It is well established that galaxies exhibit distinct intrinsic properties across varying environments, highlighting the significant role of the environment in galaxy formation and evolution. The cosmic web, characterized by the intricate arrangement of galaxies in large-scale structures, is commonly classified into four types: knots, filaments, walls, and voids. However, defining these categories poses a challenge due to the various methods by which these systems can be distinguished from one another. Moreover, considering the intricate nature of the Universe's large-scale structure, rigidly compartmentalizing galaxies into four discrete categories appears to lack the flexibility inherent in the cosmic web itself. One prevalent method for categorization involves utilizing the eigenvalues of the Hessian matrix derived from the matter distribution. By examining the ratios of these eigenvalues, we demonstrate statistically that there exists no distinct set of four characteristic values delineating discrete compartmentalized environments. Instead, a continuous distribution of these ratios reveals a complex and continuous network of environmental conditions. We apply these findings to a semi-analytical model of galaxy formation integrated with dark matter-only simulations, elucidating how galaxy intrinsic properties dynamically respond to environmental variations.