Characteristic density contrasts in the evolution of superclusters. The case of A2142 supercluster

TL;DR

This study investigates the density contrasts and dynamical evolution of the A2142 supercluster within the cosmic web, using spherical collapse models to predict future structural developments and the current state of collapse.

Contribution

It introduces a method to analyze supercluster evolution through density contrasts at different epochs, applied specifically to the A2142 supercluster, highlighting its current collapse phase.

Findings

A2142's core has begun collapsing.

The zero-gravity line marks the supercluster's outer boundary.

Future evolution may lead to multiple collapsing systems.

Abstract

The formation and evolution of the cosmic web in which galaxy superclusters are the largest relatively isolated objects is governed by a gravitational attraction of dark matter and antigravity of dark energy (cosmological constant). We study the characteristic density contrasts in the spherical collapse model for several epochs in the supercluster evolution and their dynamical state. We analysed the density contrasts for the turnaround, future collapse and zero gravity in different LCDM models and applied them to study the dynamical state of the supercluster A2142 with an almost spherical main body. The analysis of the supercluster A2142 shows that its high-density core has already started to collapse. The zero-gravity line outlines the outer region of the main body of the supercluster. In the course of future evolution the supercluster may split into several collapsing systems. The various density contrasts presented in our study and applied to the supercluster A2142 offer a promising way to characterise the dynamical state and expected future evolution of galaxy superclusters.