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