A KiDS weak lensing analysis of assembly bias in GAMA galaxy groups

Dvornik, Andrej; Cacciato, Marcello; Kuijken, Konrad; Viola, Massimo; Hoekstra, Henk; Nakajima, Reiko; van Uitert, Edo; Brouwer, Margot; Choi, Ami; Erben, Thomas; Fenech Conti, Ian; Farrow, Daniel J.; Herbonnet, Ricardo; Heymans, Catherine; Hildebrandt, Hendrik; Hopkins, Andrew M.; McFarland, John; Norberg, Peder; Schneider, Peter; Sifón, Cristóbal; Valentijn, Edwin; Wang, Lingyu

Abstract

We investigate possible signatures of halo assembly bias for spectroscopically selected galaxy groups from the Galaxy And Mass Assembly (GAMA) survey using weak lensing measurements from the spatially overlapping regions of the deeper, high-imaging-quality photometric Kilo-Degree Survey.We use GAMA groups with an apparent richness larger than 4 to identify samples with comparable mean host halo masses but with a different radial distribution of satellite galaxies, which is a proxy for the formation time of the haloes. We measure the weak lensing signal for groups with a steeper than average and with a shallower than average satellite distribution and find no sign of halo assembly bias, with the bias ratio of 0.85+0.37 −0.25, which is consistent with the cold dark matter prediction. Our galaxy groups have typical masses of 1013M h−1, naturally complementing previous studies of halo assembly bias on galaxy cluster scales.

Citation

Dvornik, A., Cacciato, M., Kuijken, K., Viola, M., Hoekstra, H., Nakajima, R., …Wang, L. (2017). A KiDS weak lensing analysis of assembly bias in GAMA galaxy groups. Monthly Notices of the Royal Astronomical Society, 468(3), 3251-3265. https://doi.org/10.1093/mnras/stx705

• Journal Article Type: Article
• Acceptance Date: Mar 20, 2017
• Online Publication Date: Mar 22, 2017
• Publication Date: Mar 22, 2017
• Deposit Date: Jul 5, 2017
• Publicly Available Date: Jul 5, 2017
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Royal Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 468
• Issue: 3
• Pages: 3251-3265
• DOI: https://doi.org/10.1093/mnras/stx705
• Public URL: https://durham-repository.worktribe.com/output/1383701