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We study the red sequence in a cluster of galaxies at z=1.62 and follow its evolution over the intervening 9.5 Gyr to the present day. Using deep YJKs imaging with the HAWK-I instrument on the VLT we identify a tight red sequence and construct its rest-frame i-band luminosity function (LF). There is a marked deficit of faint red galaxies in the cluster that causes a turnover in the LF. We compare the red sequence LF to that for clusters at z<0.8 correcting the luminosities for passive evolution. The shape of the cluster red sequence LF does not evolve between z=1.62 and z=0.6 but at z<0.6 the faint population builds up significantly. Meanwhile, between z=1.62 to 0.6 the inferred total light on the red sequence grows by a factor of about 2 and the bright end of the LF becomes more populated. We construct a simple model for red sequence evolution that grows the red sequence in total luminosity and matches the constant LF shape at z>0.6. In this model the cluster accretes blue galaxies from the field that are then quenched and subsequently allowed to merge. We find that 3--4 mergers among cluster galaxies during the 4 Gyr between z=1.62 and z=0.6 matches the observed luminosity function evolution between the two redshifts. The inferred merger rate is consistent with other studies of this cluster. Our result supports the picture that galaxy merging during the major growth phase of massive clusters is an important process in shaping the red sequence population at all luminosities.
We present an analysis of the levels and evolution of star formation activity in a representative sample of 30 massive galaxy clusters at 0.15<z<0.30 from the Local Cluster Substructure Survey (LoCuSS), combining wide-field Spitzer 24um data with ext
The variability of the spectral solar irradiance (SSI) over the course of the 11-year solar cycle is one of the manifestations of solar magnetic activity. There is a strong evidence that the SSI variability has an effect on the Earths atmosphere. The
We identified 24 SiIV absorption systems with z <~ 1 from a blind survey of 49 low-redshift quasars with archival Hubble Space Telescope ultraviolet spectra. We relied solely on the characteristic wavelength separation of the doublet to automatically
The intergalactic medium (IGM) is the dominant reservoir of baryons at all cosmic epochs. We investigate the evolution of the IGM from z=2-0 in 48 Mpc/h, 110-million particle cosmological hydrodynamic simulations using three prescriptions for galacti
Using a sample of 67 galaxies from the MIGHTEE Survey Early Science data we study the HI-based baryonic Tully-Fisher relation (bTFr), covering a period of $sim$one billion years ($0 leq z leq 0.081 $). We consider the bTFr based on two different rota