We have generated complementary halo mass estimates for all groups in the Galaxy And Mass Assembly Galaxy Group Catalogue (GAMA G3Cv1) using a modified caustic mass estimation algorithm, originally developed by Diaferio & Geller (1997). We calibrate the algorithm by applying it on a series of 9 GAMA mock galaxy light cones and investigate the effects of using different definitions for group centre and size. We select the set of parameters that provide median-unbiased mass estimates when tested on mocks, and generate mass estimates for the real group catalogue. We find that on average, the caustic mass estimates agree with dynamical mass estimates within a factor of 2 in 90.8 +/- 6.1% groups and compares equally well to velocity dispersion based mass estimates for both high and low multiplicity groups over the full range of masses probed by the G3Cv1.
@article{arxiv.1204.0510,
title = {Galaxy And Mass Assembly: Estimating galaxy group masses via caustic analysis},
author = {Mehmet Alpaslan and Aaron S. G. Robotham and Simon Driver and Peder Norberg and John A. Peacock and Ivan Baldry and Joss Bland-Hawthorn and Sarah Brough and Andrew M. Hopkins and Lee S. Kelvin and Jochen Liske and Jon Loveday and Alexander Merson and Robert C. Nichol and Kevin Pimbblet},
journal= {arXiv preprint arXiv:1204.0510},
year = {2012}
}