Galaxy And Mass Assembly (GAMA): the halo mass of galaxy groups from maximum-likelihood weak lensing

Han, J.; Eke, V.R.; Frenk, C.S.; Mandelbaum, R.; Norberg, P.; Schneider, M.D.; Peacock, J.A.; Jing, Y.; Baldry, I.; Bland-Hawthorn, J.; Brough, S.; Brown, M.J.I.; Liske, J.; Loveday, J.; Robotham, A.S.G.

doi:10.1093/mnras/stu2178

Galaxy And Mass Assembly (GAMA): the halo mass of galaxy groups from maximum-likelihood weak lensing

Han, J.; Eke, V.R.; Frenk, C.S.; Mandelbaum, R.; Norberg, P.; Schneider, M.D.; Peacock, J.A.; Jing, Y.; Baldry, I.; Bland-Hawthorn, J.; Brough, S.; Brown, M.J.I.; Liske, J.; Loveday, J.; Robotham, A.S.G.

Authors

J. Han

Dr Vincent Eke v.r.eke@durham.ac.uk
Associate Professor

Professor Carlos Frenk c.s.frenk@durham.ac.uk
Professor

R. Mandelbaum

Professor Peder Norberg peder.norberg@durham.ac.uk
Professor

M.D. Schneider

J.A. Peacock

Y. Jing

I. Baldry

J. Bland-Hawthorn

S. Brough

M.J.I. Brown

J. Liske

J. Loveday

A.S.G. Robotham

Abstract

We present a maximum-likelihood weak-lensing analysis of the mass distribution in optically selected spectroscopic Galaxy Groups (G3Cv5) in the Galaxy And Mass Assembly (GAMA) survey, using background Sloan Digital Sky Survey (SDSS) photometric galaxies. The scaling of halo mass, Mh, with various group observables is investigated. Our main results are as follows. (1) The measured relations of halo mass with group luminosity, virial volume and central galaxy stellar mass, M*, agree very well with predictions from mock group catalogues constructed from a galform semi-analytical galaxy formation model implemented in the Millennium ΛCDM N-body simulation. (2) The measured relations of halo mass with velocity dispersion and projected half-abundance radius show weak tension with mock predictions, hinting at problems in the mock galaxy dynamics and their small-scale distribution. (3) The median Mh|M* measured from weak lensing depends more sensitively on the lognormal dispersion in M* at fixed Mh than it does on the median M*|Mh. Our measurements suggest an intrinsic dispersion of σlog(M*)∼ 0.15. (4) Comparing our mass estimates with those in the catalogue, we find that the G3Cv5 mass can give biased results when used to select subsets of the group sample. Of the various new halo-mass estimators that we calibrate using our weak-lensing measurements, group luminosity is the best single-proxy estimator of group mass.

Citation

Han, J., Eke, V., Frenk, C., Mandelbaum, R., Norberg, P., Schneider, M., …Robotham, A. (2015). Galaxy And Mass Assembly (GAMA): the halo mass of galaxy groups from maximum-likelihood weak lensing. Monthly Notices of the Royal Astronomical Society, 446(2), 1356-1379. https://doi.org/10.1093/mnras/stu2178

Journal Article Type	Article
Acceptance Date	Oct 15, 2014
Online Publication Date	Nov 17, 2014
Publication Date	Jan 11, 2015
Deposit Date	Feb 3, 2016
Publicly Available Date	Feb 11, 2016
Journal	Monthly Notices of the Royal Astronomical Society
Print ISSN	0035-8711
Electronic ISSN	1365-2966
Publisher	Royal Astronomical Society
Peer Reviewed	Peer Reviewed
Volume	446
Issue	2
Pages	1356-1379
DOI	https://doi.org/10.1093/mnras/stu2178
Keywords	Gravitational lensing: weak, Methods: data analysis, Dark matter, Galaxies: clusters.

Files

Published Journal Article (1.9 Mb)
PDF

Copyright Statement
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2014 The Author Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.