1704.08871
The faint end of the red sequence galaxy luminosity function: unveiling surface brightness selection effects with the CLASH clusters
Martinet, et al
Characterizing the evolution of the faint end of the cluster red sequence (RS) galaxy luminosity function (GLF) with z is a milestone in understanding galaxy evolution. However, the community is still divided in that respect, hesitating between an enrichment of the RS due to efficient quenching of blue galaxies from z~1 to present-day or a scenario in which the RS is built at a higher z and does not evolve afterwards. Recently, it has been proposed that surface brightness (SB) selection effects could possibly solve the literature disagreement, accounting for the diminishing of the RS faint population in ground based observations. Investigate this hypothesis by comparing the RS GLFs of 16 CLASH clusters computed independently from ground-based Subaru/Suprime-Cam and HST/ACS images in the z range 0.187<=z<=0.686. Stack individual cluster GLFs in z and mass bins. Find similar RS GLFs for space and ground based data, with a difference 0.2 sigma in the faint end parameter alpha when stacking all clusters together and a maximum difference of 0.9 sigma in the case of the high z stack, demonstrating a weak dependence on the type of observations in the probed range of z and mass. When considering the full sample, estimate alpha=-0.76±0.07 and alpha=-0.78±0.06 with HST and Subaru respectively. Note a mild variation of the faint end with z at a 1.7 sigma and 2.6 sigma significance. Investigate the effect of SB dimming by simulating the low z galaxies at high z. Measure an evolution in the faint end slope of less than 1 sigma in this case, implying that the observed signature is moderately larger than one would expect from SB dimming alone, and indicating a true evolution in the faint end slope.
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