TY - JOUR
T1 - Galaxy And Mass Assembly (GAMA)
T2 - the halo mass of galaxy groups from maximum-likelihood weak lensing
AU - Han, Jiaxin
AU - Eke, Vincent R.
AU - Frenk, Carlos S.
AU - Mandelbaum, Rachel
AU - Norberg, Peder
AU - Schneider, Michael D.
AU - Peacock, John A.
AU - Jing, Yipeng
AU - Baldry, Ivan
AU - Bland-Hawthorn, Joss
AU - Brough, Sarah
AU - Brown, Michael J. I.
AU - Liske, Jochen
AU - Loveday, Jon
AU - Robotham, Aaron S. G.
PY - 2015/1/11
Y1 - 2015/1/11
N2 - We present a maximum-likelihood weak-lensing analysis of the mass distribution in optically selected spectroscopic Galaxy Groups (G(3)Cv5) in the Galaxy And Mass Assembly (GAMA) survey, using background Sloan Digital Sky Survey (SDSS) photometric galaxies. The scaling of halo mass, M-h, 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 Lambda CDM 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 M-h vertical bar M-* measured from weak lensing depends more sensitively on the lognormal dispersion in M-* at fixed Mh than it does on the median M-*vertical bar M-h. Our measurements suggest an intrinsic dispersion of sigma(log(M star)) similar to 0.15. (4) Comparing our mass estimates with those in the catalogue, we find that the G(3)Cv5 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.
AB - We present a maximum-likelihood weak-lensing analysis of the mass distribution in optically selected spectroscopic Galaxy Groups (G(3)Cv5) in the Galaxy And Mass Assembly (GAMA) survey, using background Sloan Digital Sky Survey (SDSS) photometric galaxies. The scaling of halo mass, M-h, 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 Lambda CDM 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 M-h vertical bar M-* measured from weak lensing depends more sensitively on the lognormal dispersion in M-* at fixed Mh than it does on the median M-*vertical bar M-h. Our measurements suggest an intrinsic dispersion of sigma(log(M star)) similar to 0.15. (4) Comparing our mass estimates with those in the catalogue, we find that the G(3)Cv5 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.
KW - gravitational lensing: weak
KW - methods: data analysis
KW - dark matter
KW - galaxies: clusters
KW - DARK-MATTER HALOES
KW - DIGITAL SKY SURVEY
KW - LARGE-SCALE STRUCTURE
KW - K-BAND PROPERTIES
KW - STELLAR MASS
KW - LUMINOSITY FUNCTION
KW - RADIAL-DISTRIBUTION
KW - REDSHIFT SURVEY
KW - STAR-FORMATION
KW - OCCUPATION DISTRIBUTION
U2 - 10.1093/mnras/stu2178
DO - 10.1093/mnras/stu2178
M3 - Article
VL - 446
SP - 1356
EP - 1379
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
IS - 2
ER -