The XMM Cluster Survey: testing chameleon gravity using the profiles of clusters

• Type: Article in International Scientific Journal
• Date: 2015

Authors

Wilcox, H (Author) Other; Bacon, D (Author) Other; Nichol, RC (Author) Other; Rooney, PJ (Author) Other; Terukina, A (Author) Other; Romer, AK (Author) Other; Koyama, K (Author) Other; Zhao, GB (Author) Other; Hood, R (Author) Other; Mann, RG (Author) Other; Hilton, M (Author) Other; Manolopoulou, M (Author) Other; Sahlen, M (Author) Other; Collins, CA (Author) Other; Liddle, AR (Author) Other; Mayers, JA (Author) Other; Mehrtens, N (Author) Other; Miller, CJ (Author) Other; Stott, JP (Author) Other; viana, ptp (Author) FCUP

Journal

Title: Monthly Notices of the Royal Astronomical Society

Vol. 452

Pages: 1171-1183

ISSN: 0035-8711

Publisher: Oxford University Press

Indexing

ISI Web of Knowledge - 74 Citations

Scopus - 74 Citations

Other information

Authenticus ID: P-00G-K1W

DOI: 10.1093/mnras/stv1366

Abstract (EN): 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 (beta and phi(infinity)). Our fits are consistent with general relativity, not requiring a fifth force. In the special case of f(R) gravity (where beta = root 1/6), we set an upper limit on the background field amplitude today of |f(R0)| < 6 x 10(-5) (95 per cent CL). This is one of the strongest constraints to date on |f(R0)| 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.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 13