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Weak lensing by galaxies in groups and clusters - I. Theoretical expectations

Yang, Xiaohu ; Mo, H. J. ; Van Den Bosch, Frank C. ; Jing, Y. P. ; Weinmann, Simone M. ; Meneghetti, M.

In: Monthly Notices of the Royal Astronomical Society, 2006, vol. 373, no. 3, p. 1159-1172

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    Titre
    • Weak lensing by galaxies in groups and clusters - I. Theoretical expectations
    Auteur
    • Yang, Xiaohu. Shanghai Astronomical Observatory; the Partner Group of MPA, Nandan Road 80, Shanghai 200030, China
    • Mo, H. J.. Department of Astronomy, University of Massachusetts, Amherst, MA 01003-9305, USA
    • Van Den Bosch, Frank C.. Max-Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg, Germany
    • Jing, Y. P.. Shanghai Astronomical Observatory; the Partner Group of MPA, Nandan Road 80, Shanghai 200030, China
    • Weinmann, Simone M.. Institute for Theoretical Physics, University of Zurich, CH-8057, Zurich, Switzerland
    • Meneghetti, M.. Zentrum für Astronomie, ITA, Universität Heidelberg, Albert-Überle-Str. 2, D-69120 Heidelberg, Germany
    Type de document
    • Postprint
    Langue
    • Anglais
    Publié dans
    • Monthly Notices of the Royal Astronomical Society, 2006, vol. 373, no. 3, p. 1159-1172. Blackwell Publishing Ltd
    Autre version électronique
    Identifiant OAI-PMH
    • oai:doc.rero.ch:297734
    Summary
    Galaxy-galaxy lensing is rapidly becoming one of the most promising means to accurately measure the average relation between galaxy properties and halo mass. In order to obtain a signal of sufficient signal-to-noise ratio, one needs to stack many lens galaxies according to their property of interest, such as luminosity or stellar mass. Since such a stack consists of both central and satellite galaxies, which contribute very different lensing signals, the resulting shear measurements can be difficult to interpret. In the past, galaxy-galaxy lensing studies either have completely ignored this problem, have applied rough isolation criteria in an attempt to preferentially select ‘central' galaxies, or have tried to model the contribution of satellites explicitly. However, if one is able to a priori split the galaxy population in central and satellite galaxies, one can measure their lensing signals separately. This not only allows a much cleaner measurement of the relation between halo mass and their galaxy populations, but also allows a direct measurement of the subhalo masses around satellite galaxies. In this paper, we use a realistic mock galaxy redshift survey to show that galaxy groups, properly selected from large galaxy surveys, can be used to accurately split the galaxy population in centrals and satellites. Stacking the resulting centrals according to their group mass, estimated from the total group luminosity, allows a remarkably accurate recovery of the masses and density profiles of their host haloes. In addition, stacking the corresponding satellite galaxies according to their projected distance from the group centre yields a lensing signal that can be used to accurate measure the masses of both subhaloes and host haloes. We conclude that an application of galaxy-galaxy lensing measurements to group catalogues extracted from large galaxy redshift surveys offers a unique opportunity to accurately constrain the galaxy-dark matter connection