Astronomy & Astrophysics

Issue		A&A Volume 456, Number 1, September II 2006
Page(s)		55 - 74
Section		Cosmology (including clusters of galaxies)
DOI		10.1051/0004-6361:20053650

A&A 456, 55-74 (2006)
DOI: 10.1051/0004-6361:20053650

X-ray properties in massive galaxy clusters: XMM-Newton observations of the REFLEX-DXL sample

Y.-Y. Zhang¹, H. Böhringer¹, A. Finoguenov¹, Y. Ikebe^{1, 2}, K. Matsushita^{1, 3}, P. Schuecker¹, L. Guzzo⁴ and C. A. Collins⁵

¹ Max-Planck-Institut für extraterrestrische Physik, Giessenbachstraße, 85748 Garching, Germany
e-mail: yyzhang@mpe.mpg.de
² National Museum of Emerging Science and Innovation, Tokyo, Japan
³ Tokyo University of Science, Tokyo, Japan
⁴ INAF - Osservatorio Astronomico di Brera, Merate/Milano, Italy
⁵ Liverpool John Moores University, Liverpool, UK

(Received 17 June 2005 / Accepted 5 June 2006 )

Abstract
We selected an unbiased, flux-limited and almost volume-complete sample of 13 distant, X-ray luminous (DXL, $z\sim 0.3$ ) clusters and one supplementary cluster at z=0.2578 from the REFLEX Survey (the REFLEX-DXL sample). We performed a detailed study to explore their X-ray properties using XMM-Newton observations. Based on the precise radial distributions of the gas density and temperature, we obtained robust cluster masses and gas mass fractions. The average gas mass fraction of the REFLEX-DXL sample at r₅₀₀, $0.116 \pm 0.007$ , agrees with the previous cluster studies and the WMAP baryon fraction measurement. The scaled profiles of the surface brightness, temperature, entropy, gas mass and total mass are characterized by a self-similar behaviour at radii above 0.2-0.3 r₅₀₀. The REFLEX-DXL sample confirms the previous studies of the normalization of the scaling relations (L-T, L-M, M-T and $M_{\rm gas}{-}T$ ) when the redshift evolution of the scaling relations is accounted for. We investigated the scatter of the scaling relations of the REFLEX-DXL sample. This gives the correlative scatter of (0.20, 0.10) for variable of (M, T) of the M₅₀₀-T relation, for example.

Key words: cosmology: observations -- galaxies: clusters: general -- X-rays: galaxies: clusters -- cosmology: dark matter

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