Back-in-time dynamics of the cluster IE 0657-56 (the Bullet System)

Abstract

We present a simplified dynamical model of the ``Bullet'' system of two colliding clusters. The model constrains the masses of the system by requiring that the orbits of the main and sub components satisfy the cosmological initial conditions of vanishing physical separation a Hubble time ago. This is also known as the timing argument. The model considers a system embedded in an over-dense region. We argue that a relative speed of $4500km/s$ between the two components is consistent with cosmological conditions if the system is of a total mass of $2.8\times 10^{15}{h}^{-1}{M}_{\odot }$ is embedded in a region of a (mild) over-density of 10 times the cosmological background density. Combining this with the lensing measurements of the projected mass, the model yields a ratio of 3:1 for the mass of the main relative to that of the subcomponent. The effect of the background weakens as the relative speed between the two components is decreased. For relative speeds lower than $\sim 3700km/s$, the timing argument yields masses which are too low to be consistent with lensing.

5 pages, 3 figures, submitted to MNRAS

References in corpus (9)

• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• A direct empirical proof of the existence of dark matter
• Constraints on the Self-Interaction Cross-Section of Dark Matter from Numerical Simulations of the Merging Galaxy Cluster 1E 0657-5
• Strong and weak lensing united III: Measuring the mass distribution of the merging galaxy cluster 1E0657-56
• On the Proof of Dark Matter, the Law of Gravity and the Mass of Neutrinos
• How Rare is the Bullet Cluster?
• A New Force in the Dark Sector?
• The Cluster-Merger Shock in 1E 0657-56: Faster than the Speeding Bullet?
• Timing and Lensing of the Colliding Bullet Clusters: barely enough time and gravity to accelerate the bullet

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• Radial structure, inflow & central mass of stationary radiative galaxy clusters