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Paper: The Clustering of Star-Forming and Passive Galaxies at z ∼ 2
Volume: 399, Panoramic Views of Galaxy Formation and Evolution
Page: 90
Authors: Almaini, O.; Hartley, W.; Foucaud, S.; Lane, K.; Conselice, C.J.; McLure, R.J.; Cirasuolo, M.; Dunlop, J.S.; Smail, I.; Simpson, C.
Abstract: We present early results on the clustering of galaxies at z ∼ 2, selected using the BzK colour technique from the UKIDSS Ultra-Deep Survey (UDS). The passive (pBzK) galaxies are the most strongly clustered, consistent with inhabiting dark-matter halos in excess of 1013M at these redshifts. Starforming (sBzK) galaxies are less strongly clustered, but reveal an excess of pairs on small scales (< 1Mpc) which suggest multiple halo occupation. The number counts of these populations are also markedly different, with the pBzK galaxies showing a sharp flattening beyond KAB = 21, while the counts of star-forming (sBzK) galaxies continue to rise steeply towards faint magnitudes. We conclude that only very luminous galaxies (MK(AB) < −23) are passively evolving at z ∼ 2, and these inhabit the most massive dark-matter halos. These findings are consistent with the ‘downsizing’ scenario for the build-up of the passive red sequence.
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