Halo Pairs in the Millennium Simulation: Love & Deception

TL;DR

This paper analyzes the statistical properties of close dark matter halo pairs from the Millennium Simulation, examining how different critical distances affect their evolution, lifetimes, and mass ratios.

Contribution

It provides a detailed statistical analysis of dark matter halo pairs and explores the impact of varying critical distance thresholds on their properties.

Findings

Changing dcrit affects pair separation evolution

Different dcrit values influence pair lifetimes

Mass ratios vary with critical distance

Abstract

In this work I investigate the statistical properties of a huge catalog of closely interacting pairs of dark matter haloes, extracted from the Millennium Simulation database. Only haloes that reach a minimum mass greater than 8.6 \times 10^10 Msun/h (corresponding to 100 particles) are considered. Close pairs are selected if they come within a critical distance dcrit. I explore the effects of replacing dcrit = 1 Mpc/h with 200 kpc/h on the evolution of separations, lifetimes, total masses and mass ratios of these pairs.