Observations of the Sunyaev–Zel'dovich effect in the z=0.78 cluster MS 1137.5+6625期刊界 All Journals 搜尽天下杂志传播学术成果专业期刊搜索期刊信息化学术搜索

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Observations of the Sunyaev–Zel'dovich effect in the z=0.78 cluster MS 1137.5+6625

Authors:	Garret Cotter Helen J Buttery Rhiju Das† Michael E Jones Keith Grainge G G Pooley Richard Saunders

Institution:	Astrophysics, Cavendish Laboratory, Madingley Road, Cambridge CB3 0HE

Abstract:	We have observed the z =0.78 cluster MS 1137.5+6625 with the Ryle Telescope (RT) at 15 GHz. After subtraction of contaminating radio sources in the field, we find a Sunyaev–Zel'dovich flux decrement of -421±60 μJy on the ≈0.65 k λ baseline of the RT, spatially coincident with the optical and X-ray positions for the cluster core. For a spherical King-profile cluster model, the best fit to our flux measurement has a core radius θ _C=20 arcsec , consistent with previous X-ray observations, and a central temperature decrement Δ T =650±92 μK . Using this model, we calculate that the cluster has a gas mass inside a radius of 2.9×10¹³ M_⊙ for an Ω_M=1 universe and 1.6×10¹³ M_⊙ for Ω_M=0.3 , Ω_Λ=0.7 . We compare this model with existing measurements of the total mass of the cluster, based on gravitational lensing, and estimate a gas fraction for MS 1137.5+6625 of ≈8 per cent.

Keywords:	galaxies: clusters: individual: MS 1137 5+6625 cosmology: observations