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Weak Lensing Calibrated M-T Scaling Relation of Galaxy Groups in the COSMOS Field

Kettula, K. and Finoguenov, A. and Massey, R. and Rhodes, J. and Hoekstra, H. and Taylor, J. E. and Spinelli, P. F. and Tanaka, M. and Ilbert, O. and Capak, P. and McCracken, H. J. and Koekemoer, A. (2013) Weak Lensing Calibrated M-T Scaling Relation of Galaxy Groups in the COSMOS Field. Astrophysical Journal, 778 (1). Art. No. 74. ISSN 0004-637X. doi:10.1088/0004-637X/778/1/74.

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The scaling between X-ray observables and mass for galaxy clusters and groups is instrumental for cluster-based cosmology and an important probe for the thermodynamics of the intracluster gas. We calibrate a scaling relation between the weak lensing mass and X-ray spectroscopic temperature for 10 galaxy groups in the COSMOS field, combined with 55 higher-mass clusters from the literature. The COSMOS data includes Hubble Space Telescope imaging and redshift measurements of 46 source galaxies per arcminute2, enabling us to perform unique weak lensing measurements of low-mass systems. Our sample extends the mass range of the lensing calibrated M-T relation an order of magnitude lower than any previous study, resulting in a power-law slope of 1.48^(+0.13)_(-0.09). The slope is consistent with the self-similar model, predictions from simulations, and observations of clusters. However, X-ray observations relying on mass measurements derived under the assumption of hydrostatic equilibrium have indicated that masses at group scales are lower than expected. Both simulations and observations suggest that hydrostatic mass measurements can be biased low. Our external weak lensing masses provide the first observational support for hydrostatic mass bias at group level, showing an increasing bias with decreasing temperature and reaching a level of 30%-50% at 1 keV.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Finoguenov, A.0000-0002-4606-5403
Massey, R.0000-0002-6085-3780
Rhodes, J.0000-0002-4485-8549
Tanaka, M.0000-0002-5011-5178
Ilbert, O.0000-0002-7303-4397
Capak, P.0000-0003-3578-6843
McCracken, H. J.0000-0002-9489-7765
Koekemoer, A.0000-0002-6610-2048
Additional Information:© 2013 American Astronomical Society. Received 2013 June 20; accepted 2013 September 25; published 2013 November 6. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA Inc., under NASA contract NAS 5-26555. Also based on data collected at the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan; the XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA; the European Southern Observatory under Large Program 175.A-0839, Chile; Kitt Peak National Observatory, Cerro Tololo Inter-American Observatory, and the National Optical Astronomy Observatory, which are operated by the Association of Universities for Research in Astronomy, Inc. (AURA) under cooperative agreement with the National Science Foundation; the National Radio Astronomy Observatory, which is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.; and the Canada–France–Hawaii Telescope (CFHT) with MegaPrime/MegaCam operated as a joint project by the CFHT Corporation, CEA/DAPNIA, the National Research Council of Canada, the Canadian Astronomy Data Centre, the Centre National de la Recherche Scientifique de France, TERAPIX, and the University of Hawaii. The authors thank F. Miniati for useful discussion. K.K. acknowledges support from the Magnus Ehrnrooth Foundation. A.F. acknowledges the Academy of Finland (decision 266918). R.M. is supported by a Royal Society University Research Fellowship and ERC grant MIRG-CT-208994. J.R. was supported by JPL, which is run by Caltech under a contract for NASA. H.H. acknowledges NWO Vidi grant 639.042.814. This research has made use of NASA’s Astrophysics Data System. Facilities: HST (ACS), XMM (EPIC).
Group:COSMOS, Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
Magnus Ehrnrooth FoundationUNSPECIFIED
Academy of Finland266918
European Research Council (ERC)MIRG-CT-208994
Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO)639.042.814
Subject Keywords:cosmology: observations; galaxies: groups: general; gravitational lensing: weak
Issue or Number:1
Record Number:CaltechAUTHORS:20131224-072259005
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Official Citation:Weak Lensing Calibrated M-T Scaling Relation of Galaxy Groups in the COSMOS Field K. Kettula et al. 2013 ApJ 778 74
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:43157
Deposited On:24 Dec 2013 15:42
Last Modified:10 Nov 2021 16:33

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