Journal Article

Galaxy And Mass Assembly (GAMA): estimating galaxy group masses via caustic analysis

Mehmet Alpaslan, Aaron S. G. Robotham, Simon Driver, Peder Norberg, John A. Peacock, Ivan Baldry, Joss Bland-Hawthorn, Sarah Brough, Andrew M. Hopkins, Lee S. Kelvin, Jochen Liske, Jon Loveday, Alexander Merson, Robert C. Nichol and Kevin Pimbblet

in Monthly Notices of the Royal Astronomical Society

Published on behalf of The Royal Astronomical Society

Volume 426, issue 4, pages 2832-2846
Published in print November 2012 | ISSN: 0035-8711
Published online November 2012 | e-ISSN: 1365-2966 | DOI: http://dx.doi.org/10.1111/j.1365-2966.2012.21020.x
Galaxy And Mass Assembly (GAMA): estimating galaxy group masses via caustic analysis

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Abstract

We have generated complementary halo mass estimates for all the groups in the Galaxy And Mass Assembly Galaxy Group Catalogue (GAMA G3Cv1) using a modified caustic mass estimation algorithm, originally developed by Diaferio & Geller. We calibrate the algorithm by applying it on a series of nine 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 per cent groups and compare 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.

Keywords: galaxies: groups: general; galaxies: haloes; dark matter; large-scale structure of Universe

Journal Article.  8697 words.  Illustrated.

Subjects: Astronomy and Astrophysics

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