Evolution of the luminosity-to-halo mass relation of LRGs from a combined analysis of SDSS-DR10+RCS2

Abstract

We study the evolution of the luminosity-to-halo mass relation of luminous red galaxies (LRGs). We selected a sample of 52 000 LOWZ and CMASS LRGs from the Baryon Oscillation Spectroscopic Survey (BOSS) SDSS-DR10 in the ∼450 deg 2 that overlaps with imaging data from the second Red-sequence Cluster Survey (RCS2), grouped them into bins of absolute magnitude and redshift and measured their weak-lensing signals. The source redshift distribution has a median of 0.7, which allowed us to study the lensing signal as a function of lens redshift. We interpreted the lensing signal using a halo model, from which we obtained the halo masses as well as the normalisations of the mass-concentration relations. The concentration of haloes that host LRGs is consistent with dark-matter-only simulations once we allow for miscentering or satellites in the modelling. The slope of the luminosity-to-halo mass relation has a typical value of 1.4 and does not change with redshift, but we find evidence for a change in amplitude: the average halo mass of LOWZ galaxies increases by 25 +16 −14 % between z = 0.36 and 0.22 to an average value of (6.43 ± 0.52) × 10 13 h −1 70 M . If we extend the redshift range using the CMASS galaxies and assume that they are the progenitors of the LOWZ sample, the average mass of LRGs increases by 80 +39 −28 % between z = 0.6 and 0.2.

Intrinsic alignment of redMaPPer clusters: cluster shape–matter density correlation

“…Our results are indicated by the stars. We also show literature results for luminous red galaxies from Singh et al (2015) and Joachimi et al (2011); the masses for these samples were determined from their mean luminosities using the luminosity-to-halo mass relation from van Uitert et al (2015). The solid line indicates the best-fitting linear relation between the log 10 of halo mass and the IA amplitude, and the orange contours indicate the 1σ model uncertainty of this fit.…”

“…van Uitert et al (2015), which was determined for LOWZ and CMASS galaxies (Dawson et al 2013) in two separate, non-overlapping redshift bins each (hence four redshift bins in total), covering a redshift range from z = 0.2 to z = 0.6. The relation in each redshift bin was parametrized as M = M0,L(L/L0) β L , with a pivot luminosity L0 = 10 11 h −2 70 L⊙.…”

“…The relation in each redshift bin was parametrized as M = M0,L(L/L0) β L , with a pivot luminosity L0 = 10 11 h −2 70 L⊙. We took a weighted mean of the amplitude and slope of the luminosity-to-halo mass relation for the two LOWZ redshift bins (at 0.15 < z < 0.29 and 0.29 < z < 0.43) from van Uitert et al (2015), resulting in M0,L = 5.68 ± 0.34 × 10 13 h −1…”

“…Joachimi et al (2011) applied an additional colour cut to the MegaZ-LRG a different overdensity, they were derived using a different massconcentration relation, and they did not account for the scatter in the luminosity-to-halo mass relation. Since we needed to convert the luminosities of Joachimi et al (2011) with the scaling relations from van Uitert et al (2015) anyway, we decided to use the same scaling relations to convert the luminosities from Singh et al (2015), for consistency and for easing a comparison of results.…”

The Halo Boundary of Galaxy Clusters in the SDSS

“…The large number of REDMAPPER clusters and galaxies detected in SDSS make this data set the best currently available for measuring the galaxy density profile around clusters. We extend the modeling of M16 to include an important source of systematic error: the miscentering of halos in the cluster catalogs (George et al 2012;Rykoff et al 2014;Hoshino et al 2015;van Uitert et al 2015). Using these improved models, we explore whether the data favor the truncated Einasto model introduced by Diemer & Kravtsov (2014) to describe the splashback feature over a pure Einasto model (Sérsic 1963;Einasto 1965).…”