The Mass Distribution of the Unusual Merging Cluster Abell 2146 from Strong Lensing

Abstract

Abell 2146 consists of two galaxy clusters that have recently collided close to the plane of the sky, and it is unique in showing two large shocks on $\text{Chandra X-ray Observatory}$ images. With an early stage merger, shortly after first core passage, one would expect the cluster galaxies and the dark matter to be leading the X-ray emitting plasma. In this regard, the cluster Abell 2146-A is very unusual in that the X-ray cool core appears to lead, rather than lag, the Brightest Cluster Galaxy (BCG) in their trajectories. Here we present a strong lensing analysis of multiple image systems identified on $\text{Hubble Space Telescope}$ images. In particular, we focus on the distribution of mass in Abell 2146-A in order to determine the centroid of the dark matter halo. We use object colours and morphologies to identify multiple image systems; very conservatively, four of these systems are used as constraints on a lens mass model. We find that the centroid of the dark matter halo, constrained using the strongly lensed features, is coincident with the BCG, with an offset of $\approx$ 2 kpc between the centres of the dark matter halo and the BCG. Thus from the strong lensing model, the X-ray cool core also leads the centroid of the dark matter in Abell 2146-A, with an offset of $\approx$ 30 kpc.

13 pages, 9 figures. Accepted for publication in MNRAS

References in corpus (12)

• A direct empirical proof of the existence of dark matter
• Bayes in the sky: Bayesian inference and model selection in cosmology
• Constraints on the Self-Interaction Cross-Section of Dark Matter from Numerical Simulations of the Merging Galaxy Cluster 1E 0657-5
• Shocks and cold fronts in galaxy clusters
• A Bayesian approach to strong lensing modelling of galaxy clusters
• The non-gravitational interactions of dark matter in colliding galaxy clusters
• Combining Strong and Weak Gravitational Lensing in Abell 1689
• The behaviour of dark matter associated with 4 bright cluster galaxies in the 10kpc core of Abell 3827
• Chandra observation of two shock fronts in the merging galaxy cluster Abell 2146
• Where is the matter in the Merging Cluster Abell 2218?
• The Mass Distribution of the Strong Lensing Cluster SDSS J1531+3414
• The Distribution of Dark and Luminous Matter in the Unique Galaxy Cluster Merger Abell 2146

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