The abundance and colours of galaxies in high-redshift clusters in the cold dark matter cosmology

Abstract

High redshift galaxy clusters allow us to examine galaxy formation in extreme environments.Here we compile data for 15 z > 1 galaxy clusters to test the predictions from a state-of-theart semi-analytical model of galaxy formation. The model gives a good match to the slope and zero-point of the cluster red sequence. The model is able to match the cluster galaxy luminosity function at faint and bright magnitudes, but under-estimates the number of galaxies around the break in the cluster luminosity function. We find that simply assuming a weaker dust attenuation improves the model predictions for the cluster galaxy luminosity function, but worsens the predictions for the red sequence at bright magnitudes. Examination of the properties of the bright cluster galaxies suggests that the default dust attenuation is large due to these galaxies having large reservoirs of cold gas as well as small radii. We find that matching the luminosity function and colours of high redshift cluster galaxies, whilst remaining consistent with local observations, poses a challenge for galaxy formation models.

The Next Generation Virgo Cluster Survey (NGVS). XXIV. The Red Sequence to ∼106 L⊙ and Comparisons with Galaxy Formation Models

“…On a related note, Licitra et al (2016) have shown that clusters at z < 1 in SAMs suffer from ETG populations with too low an abundance and too blue colors, while ∼10% of model clusters have positive RS slopes. On the other hand, Merson et al (2016) found broad consistency between observations and SAMs in the zeropoint and slope of the RS in z > 1 clusters. This suggests that errors creep into the evolution of cluster galaxies in SAMs at z < 1.…”

The galaxy population in cold and warm dark matter cosmologies

“…The GP14 model was calibrated on the MS-W7 simulation (Guo et al 2013;Lacey et al 2016a), which adopts the same WMAP7 cosmology as the simulations used in this work but has a much larger volume (500h −1 M pc) 3 and a lower mass resolution of 9.35 × 10 8 h −1 M⊙. The GP14 model successfully reproduces a wide range of observations (Gonzalez-Perez et al 2014;Lagos et al 2015;Merson et al 2016).…”

Apples to apples A2– I. Realistic galaxy simulated catalogues and photometric redshift predictions for next-generation surveys

“…Ascaso et al 2008;Mei et al 2009;Ascaso et al 2014b) in agreement with Merson et al (2015). PhotReal overcomes this problem by re-computing the photometry and therefore, shifting some galaxies from the red sequence to the blue cloud.…”