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arXiv · 1507.00737

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

Cristóbal Sifón·Marcello Cacciato·Henk Hoekstra·Margot Brouwer·Edo van Uitert·Massimo Viola·Ivan Baldry·Sarah Brough·Michael J. I. Brown·Ami Choi·Simon P. Driver·Thomas Erben·Aniello Grado·Catherine Heymans·Hendrik Hildebrandt·Benjamin Joachimi·Jelte T. A. de Jong·Konrad Kuijken·John McFarland·Lance Miller·Reiko Nakajima·Nicola Napolitano·Peder Norberg·Aaron S. G. Robotham·Peter Schneider·Gijs Verdoes Kleijn
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Abstract

We use the first 100 sq. deg. of overlap between the Kilo-Degree Survey (KiDS) and the Galaxy And Mass Assembly (GAMA) survey to determine the galaxy halo mass of ~10,000 spectroscopically-confirmed satellite galaxies in massive ($M > 10^{13}h^{-1}{\rm M}_\odot$) 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 (NFW) density profiles, fully accounting for the data covariance. The probed satellite galaxies in these groups have total masses $\log M_{\rm sub} /(h^{-1}{\rm M}_\odot) \approx 11.7 - 12.2$ consistent across group-centric distance within the errorbars. Given their typical stellar masses, $\log M_{\rm \star,sat}/(h^{-2}{\rm M}_\odot) \sim 10.5$, such total masses imply stellar mass fractions of $M_{\rm \star,sat} /M_{\rm sub} \approx 0.04 h^{-1}$ . The average subhalo hosting these satellite galaxies has a mass $M_{\rm sub} \sim 0.015M_{\rm host}$ independent of host halo mass, in broad agreement with the expectations of structure formation in a $\Lambda$CDM universe.

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Cristóbal Sifón, Marcello Cacciato, Henk Hoekstra, Margot Brouwer, Edo van Uitert, Massimo Viola, Ivan Baldry, Sarah Brough, Michael J. I. Brown, Ami Choi, Simon P. Driver, Thomas Erben, Aniello Grado, Catherine Heymans, Hendrik Hildebrandt, Benjamin Joachimi, Jelte T. A. de Jong, Konrad Kuijken, John McFarland, Lance Miller, Reiko Nakajima, Nicola Napolitano, Peder Norberg, Aaron S. G. Robotham, Peter Schneider, Gijs Verdoes Kleijn. 2015-07-02. The masses of satellites in GAMA galaxy groups from 100 square degrees of KiDS weak lensing data. https://doi.org/10.1093/mnras/stv2051

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