The mass distribution of the unusual merging cluster Abell 2146 from strong lensing

Coleman, Joseph E.; King, Lindsay J.; Oguri, Masamune; Russell, Helen R.; Canning, Rebecca E.A.; Leonard, Adrienne; Santana, Rebecca; White, Jacob A.; Baum, Stefi A.; Clowe, Douglas I.; Edge, Alastair; Fabian, Andrew C.; McNamara, Brian R.; O'Dea, Christopher P.

doi:10.1093/mnras/stw2425

The mass distribution of the unusual merging cluster Abell 2146 from strong lensing

Coleman, Joseph E.; King, Lindsay J.; Oguri, Masamune; Russell, Helen R.; Canning, Rebecca E.A.; Leonard, Adrienne; Santana, Rebecca; White, Jacob A.; Baum, Stefi A.; Clowe, Douglas I.; Edge, Alastair; Fabian, Andrew C.; McNamara, Brian R.; O'Dea, Christopher P.

Authors

Joseph E. Coleman

Lindsay J. King

Masamune Oguri

Helen R. Russell

Rebecca E.A. Canning

Adrienne Leonard

Rebecca Santana

Jacob A. White

Stefi A. Baum

Douglas I. Clowe

Professor Alastair Edge alastair.edge@durham.ac.uk
Professor

Andrew C. Fabian

Brian R. McNamara

Christopher P. O'Dea

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 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 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 ≈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 ≈30 kpc.

Citation

Coleman, J. E., King, L. J., Oguri, M., Russell, H. R., Canning, R. E., Leonard, A., …O'Dea, C. P. (2017). The mass distribution of the unusual merging cluster Abell 2146 from strong lensing. Monthly Notices of the Royal Astronomical Society, 464(2), 2469-2480. https://doi.org/10.1093/mnras/stw2425

Journal Article Type	Article
Acceptance Date	Sep 23, 2016
Online Publication Date	Sep 26, 2016
Publication Date	Jan 11, 2017
Deposit Date	Apr 28, 2017
Publicly Available Date	May 9, 2017
Journal	Monthly Notices of the Royal Astronomical Society
Print ISSN	0035-8711
Electronic ISSN	1365-2966
Publisher	Royal Astronomical Society
Peer Reviewed	Peer Reviewed
Volume	464
Issue	2
Pages	2469-2480
DOI	https://doi.org/10.1093/mnras/stw2425
Related Public URLs	arxiv.org/pdf/1609.06765.pdf

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Copyright Statement
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.