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Combined analysis of weak lensing and X-ray blind surveys

Bergé, Joel and Pacaud, Florian and Refregier, Alexandre and Massey, Richard and Pierre, Marguerite and Amara, Adam and Birkinshaw, Mark and Paulin-Henriksson, Stéphane and Smith, Graham P. and Willis, Jon (2008) Combined analysis of weak lensing and X-ray blind surveys. Monthly Notices of the Royal Astronomical Society, 385 (2). pp. 695-707. ISSN 0035-8711. doi:10.1111/j.1365-2966.2008.12902.x.

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We present a joint weak lensing and X-ray analysis of 4 deg^2 from the CFHTLS and XMMLSS surveys. Our weak lensing analysis is the first analysis of a real survey using shapelets, a new generation weak lensing analysis method. We create projected mass maps of the images, and extract six weak-lensing-detected clusters of galaxies. We show that their counts can be used to constrain the power-spectrum normalization σ8 = 0.92^(+0.26)_(−0.30) for Ωm = 0.24. We show that despite the large scatter generally observed in the mass–temperature (M–T) relation derived from lensing masses, tight constraints on both its slope and normalization M∗ can be obtained with a moderate number of sources provided that the covered mass range is large enough. Adding clusters given by Bardeau et al. to our sample, we measure M∗ =2.71^(+0.79)_(−0.61) × 10^(14) h^(−1) Mסּ. Although they are dominated by shot noise and sample variance, our measurements are consistent with currently favoured values, and set the stage for future surveys. We thus investigate the dependence of those estimates on survey size, depth and integration time, for joint weak lensing and X-ray surveys. We show that deep surveys should be dedicated to the study of the physics of clusters and groups of galaxies. For a given exposure time, wide surveys provide a larger number of detected clusters and are therefore preferred for the measurement of cosmological parameters, such as σ8 and M∗.We show that a wide survey of a few hundred square degrees is needed to improve upon current measurements of these parameters. More ambitious surveys covering 7000 deg^2 will provide the 1 per cent accuracy in the estimation of the power-spectrum and the M–T relation normalizations.

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Massey, Richard0000-0002-6085-3780
Smith, Graham P.0000-0003-4494-8277
Additional Information:© 2008 RAS, MNRAS. Accepted 2007 December 19. Received 2007 December 19; in original form 2007 August 29. Based on observations obtained with MegaPrime/MegaCam, a joint project of Canada–France–Hawaii Telescope (CFHT) and CEA/DAPNIA, at the CFHT which is operated by the National Research Council (NRC) of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique (CNRS) of France and the University of Hawaii. This work is based in part on data products produced at TERAPIX and the Canadian Astronomy Data Centre as part of the Canada–France–Hawaii Telescope Legacy Survey, a collaborative project of NRC and CNRS. It makes use of photometric redshifts produced jointly by TERAPIX and VVDS teams. The authors wish to thank Hervé Aussel, Krys Libbrecht, Jean-Baptiste Melin, Yannick Mellier, Sandrine Pires, Trevor Ponman, Jean-Luc Starck, Geneviéve Soucail and Romain Teyssier for useful discussions, and Cathy Horellou for comments on the first version of the paper.
Subject Keywords:gravitational lensing; surveys; cosmological parameters; dark matter; large-scale structure of Universe; X-rays : galaxies : clusters.
Issue or Number:2
Record Number:CaltechAUTHORS:20090407-093201816
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:13863
Deposited By: Ruth Sustaita
Deposited On:15 Jul 2009 21:27
Last Modified:08 Nov 2021 22:41

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