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The XMM cluster survey: Testing chameleon gravity using the profiles of clusters

Wilcox, H, Bacon, D, Nichol, RC, Koyama, K, Zhao, G-B, Rooney, PJ, Kathy Romer, A, Mayers, JA, Terukina, A, Hood, R, Mann, RG, Manolopoulou, M, Liddle, AR, Hilton, M, Sahlén, M, Collins, CA, Mehrtens, N, Miller, CJ, Stott, JP and Viana, PTP (2015) The XMM cluster survey: Testing chameleon gravity using the profiles of clusters. Monthly Notices of the Royal Astronomical Society, 452 (2). pp. 1171-1183. ISSN 0035-8711

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The chameleon gravity model postulates the existence of a scalar field that couples with matter to mediate a fifth force. If it exists, this fifth force would influence the hot X-ray emitting gas filling the potential wells of galaxy clusters. However, it would not influence the clusters weak lensing signal. Therefore, by comparing X-ray and weak lensing profiles, one can place upper limits on the strength of a fifth force. This technique has been attempted before using a single, nearby cluster (Coma, z = 0.02). Here we apply the technique to the stacked profiles of 58 clusters at higher redshifts (0.1 < z < 1.2), including 12 new to the literature, using X-ray data from the XMM Cluster Survey and weak lensing data from the Canada-France-Hawaii-Telescope Lensing Survey. Using a multiparameter Markov chain Monte Carlo analysis, we constrain the two chameleon gravity parameters (β and ϕ∞). Our fits are consistent with general relativity, not requiring a fifth force. In the special case of f(R) gravity (where β = √1/6), we set an upper limit on the background field amplitude today of |f<inf>R0</inf>| < 6 × 10-5 (95 per cent CL). This is one of the strongest constraints to date on |f<inf>R0</inf>| on cosmological scales. We hope to improve this constraint in future by extending the study to hundreds of clusters using data from the Dark Energy Survey.

Item Type: Article
Additional Information: This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2015 C.A. Collins et al. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
Uncontrolled Keywords: 0201 Astronomical And Space Sciences
Subjects: Q Science > QB Astronomy
Divisions: Astrophysics Research Institute
Publisher: Oxford Universitty Press
Date Deposited: 09 Sep 2015 10:44
Last Modified: 04 Sep 2021 13:59
DOI or ID number: 10.1093/mnras/stv1366
URI: https://researchonline.ljmu.ac.uk/id/eprint/1976
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