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تسجيل مستخدم جديدA KiDS weak lensing analysis of assembly bias in GAMA galaxy groups
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We investigate possible signatures of halo assembly bias for spectroscopically selected galaxy groups from the GAMA survey using weak lensing measurements from the spatially overlapping regions of the deeper, high-imaging-quality photometric KiDS 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 $Lambda$CDM prediction. Our galaxy groups have typical masses of $10^{13} M_{odot}/h$, naturally complementing previous studies of halo assembly bias on galaxy cluster scales.
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