The cosmic web around the Coma cluster from constrained cosmological simulations: I. Filaments connected to Coma at $z = 0$

TL;DR

This study uses constrained cosmological simulations to analyze the filament connections of the Coma galaxy cluster, revealing that matter accretion is more collimated along filaments compared to isotropic inflow.

Contribution

It introduces the first simulation-based analysis of Coma's filament connections, comparing simulated structures with observations to understand matter accretion patterns.

Findings

Filaments connected to Coma are accurately reproduced in simulations.

Matter accretion onto Coma is more collimated along filaments.

Simulated accretion flux is not significantly larger than average.

Abstract

Galaxy clusters in the Universe occupy the important position of nodes of the cosmic web. They are connected among them by filaments, elongated structures composed of dark matter, galaxies, and gas. The connection of galaxy clusters to filaments is important, as it is related to the process of matter accretion onto the former. For this reason, investigating the connections to the cosmic web of massive clusters, especially well known ones for which a lot of information is available, is a hot topic in astrophysics. In a previous work we performed an analysis of the filament connections of the Coma cluster of galaxies, as detected from the observed galaxy distribution. In this work we resort to a numerical simulation whose initial conditions are constrained to reproduce the Local Universe, including the region of the Coma cluster to interpret our observations in an evolutionary context. We detect the filaments connected to the simulated Coma cluster and perform an accurate comparison with the cosmic web configuration we detected in observations. We perform an analysis of the halos' spatial and velocity distributions close to the filaments in the cluster outskirts. We conclude that, although not significantly larger than the average, the flux of accreting matter on the simulated Coma cluster is significantly more collimated close to the filaments with respect to the general isotropic accretion flux. This paper is the first example of such a result and the first installment in a series of publications which will explore the build-up of the Coma cluster system in connection to the filaments of the cosmic web as a function of redshift.