The masses of satellites in GAMA galaxy groups from 100 square degrees of KiDS weak lensing data

Sifon, C.; Cacciato, M.; Hoekstra, H.; Brouwer, M.; Uitert, E.; Viola, M.; Baldry, I.; Brough, S.; Brown, M. J. I.; Choi, A.; Driver, S. P.; Erben, T.; Grado, A.; Heymans, C.; Hildebrandt, H.; Joachimi, B.; De Jong, J. T. A.; Kuijken, K.; Mcfarland, J.; Miller, L.; Nakajima, R.; Napolitano, N.; Norberg, P.; Robotham, A. S. G.; Schneider, P.; Kleijn, G. V.

doi:10.1093/mnras/stv2051

We use the first 100 deg2 of overlap between the Kilo-Degree Survey and the Galaxy AndMass Assembly survey to determine the average galaxy halomass of~10 000 spectroscopically confirmed satellite galaxies in massive (M > 1013 h-1 M⊙) galaxy groups. Separating the sample as a function of projected distance to the group centre, we jointly model the satellites and their host groups with Navarro-Frenk-White density profiles, fully accounting for the data covariance. The probed satellite galaxies in these groups have total masses log 〈Msub/(h-1 M⊙〉≈ 11.7-12.2 consistent across group-centric distance within the errorbars. Given their typical stellar masses, log 〈M*, sat/(h-2 M⊙)〉 ~ 10.5, such total masses imply stellar mass fractions of 〈M*,sat〉/〈Msub〉 ≈ 0.04 h-1. The average subhalo hosting these satellite galaxies has a mass Msub ~ 0.015 Mhost independent of host halo mass, in broad agreement with the expectations of structure formation in a Λ cold dark matter universe.

The masses of satellites in GAMA galaxy groups from 100 square degrees of KiDS weak lensing data / Sifon, C., Cacciato, M., Hoekstra, H., Brouwer, M., Uitert, E., Viola, M., Baldry, I., Brough, S., Brown, M.J.I., Choi, A., Driver, S.P., Erben, T., Grado, A., Heymans, C., Hildebrandt, H., Joachimi, B., de Jong, J.T.A., Kuijken, K., Mcfarland, J., Miller, L., et al.. - In: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY. - ISSN 0035-8711. - 454:4(2015), pp. 3938-3951. [10.1093/mnras/stv2051]