Dark matter halo properties of GAMA galaxy groups from 100 square degrees of KiDS weak lensing data
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The Kilo-Degree Survey is an optical wide-field survey designed to map the matter distribution in the Universe using weak gravitational lensing. In this paper, we use these data to measure the density profiles and masses of a sample of ~1400 spectroscopically identified galaxy groups and clusters from the Galaxy And Mass Assembly survey. We detect a highly significant signal (signal-to-noise-ratio ~120), allowing us to study the properties of dark matter haloes over one and a half order of magnitude in mass, from M ~ 1013-1014.5 h-1M⊙. We interpret the results for various subsamples of groups using a halo model framework which accounts for the mis-centring of the brightest cluster galaxy (used as the tracer of the group centre) with respect to the centre of the group's dark matter halo. We find that the density profiles of the haloes are well described by an NFW profile with concentrations that agree with predictions from numerical simulations. In addition, we constrain scaling relations between the mass and a number of observable group properties. We find that the mass scales with the total r-band luminosity as a power law with slope 1.16 ± 0.13 (1σ) and with the group velocity dispersion as a power law with slope 1.89 ± 0.27 (1σ). Finally, we demonstrate the potential of weak lensing studies of groups to discriminate between models of baryonic feedback at group scales by comparing our results with the predictions from the Cosmo-OverWhelmingly Large Simulations project, ruling out models without AGN feedback.
Viola , M , Cacciato , M , Brouwer , M , Kuijken , K , Hoekstra , H , Norberg , P , Robotham , A S G , Van Uitert , E , Alpaslan , M , Baldry , I K , Choi , A , De Jong , J T A , Driver , S P , Erben , T , Grado , A , Graham , A W , Heymans , C , Hildebrandt , H , Hopkins , A M , Irisarri , N , Joachimi , B , Loveday , J , Miller , L , Nakajima , R , Schneider , P , Sifón , C & Verdoes Kleijn , G 2015 , ' Dark matter halo properties of GAMA galaxy groups from 100 square degrees of KiDS weak lensing data ' Monthly Notices of the Royal Astronomical Society , vol 452 , no. 4 , pp. 3529-3550 . DOI: 10.1093/mnras/stv1447
Monthly Notices of the Royal Astronomical Society
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society. © 2015 The Authors, Published by Oxford University Press on behalf of the Royal Astronomical Society
DescriptionMV, MC, HHo, CS, AC, and CH acknowledge support from the European Research Council under FP7 grant number 279396 (MV, MC, CS, H.Ho) and 240185 (AC and CH). BJ acknowledges support by an STFC Ernest Rutherford Fellowship, grant reference ST/J004421/1. EvU acknowledges support from an STFC Ernest Rutherford Research Grant, grant reference ST/L00285X/1. PN acknowledges the support of the Royal Society through the award of a University Research Fellowship, the European Research Council, through receipt of a Starting Grant (DEGAS-259586) and support of the Science and Technology Facilities Council (ST/L00075X/1). RN and EvU acknowledge support from the German Federal Ministry for Economic Affairs and Energy (BMWi) provided via DLR under project no. 50QE1103. HHi is supported by the DFG Emmy Noether grant Hi 1495/2-1. This work is supported by the Netherlands Organization for Scientific Research (NWO) through grants 614.001.103 (MV) and 614.061.610 (JdJ) and by the Deutsche Forschungsgemeinschaft in the framework of the TR33 ‘The Dark Universe’. Date of Acceptance: 26/06/2015
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