AMICO galaxy clusters in KiDS-DR3

Abstract

Context. The large-scale mass distribution around dark matter haloes hosting galaxy clusters provides sensitive cosmological information. Aims. In this work we make use of a large photometric galaxy cluster sample, constructed from the public Third Data Release of the Kilo-Degree Survey, and the corresponding shear signal, to assess cluster masses and test the concordance Λ-cold dark matter (ΛCDM) model. In particular, we study the weak gravitational lensing effects on scales beyond the cluster virial radius, where the signal is dominated by correlated and uncorrelated matter density distributions along the line of sight. The analysed catalogue consists of 6962 galaxy clusters, in the redshift range 0.1 ≤ z ≤ 0.6 and with signal-to-noise ratios higher than 3.5. Methods. We perform a full Bayesian analysis to model the stacked shear profiles of these clusters. The adopted likelihood function considers both the small-scale one-halo term, used primarily to constrain the cluster structural properties, and the two-halo term, that can be used to constrain cosmological parameters. Results. We find that the adopted modelling is successful in assessing both the cluster masses and the total matter density parameter, ΩM, when fitting shear profiles up to the largest available scales of 35 Mpc h−1. Moreover, our results provide a strong observational evidence of the two-halo signal in the stacked gravitational lensing of galaxy clusters, further demonstrating the reliability of this probe for cosmological studies. The main result of this work is a robust constraint on ΩM, assuming a flat ΛCDM cosmology. We get ΩM = 0.29 ± 0.02, estimated from the full posterior probability distribution, consistent with the estimates from cosmic microwave background experiments.

AMICO galaxy clusters in KiDS-DR3: The impact of estimator statistics on the luminosity-mass scaling relation

“…A dominant source of systematic bias in stacked weak lensing analyses is a miscentering of the lenses, which can be due to an offset of the cluster halo with the visible distribution of galaxies (see, e.g., George et al 2012) or the resolution of the cluster detection method (less than 0.1 Mpc h −1 for AMICO; see Bellagamba et al 2018). Following Johnston et al (2007) as well as numerous subsequent works (e.g., Oguri et al 2010;Viola et al 2015;Dvornik et al 2017;Bellagamba et al 2019;Giocoli et al 2021), we allowed a fraction, p off , of clusters to be offset from the center of the galaxy distribution, effectively smoothing the central stacked ∆Σ profile with a characteristic radius, R off .…”

Exploring the Mass and Redshift Dependencies of the Cluster Pressure Profile with Stacks on Thermal Sunyaev–Zel’dovich Maps

“…For the stacking analysis, this would imply that the reconstructed profile is artificially diluted, meaning that we actually measure a mean "offset" profile q ¯( ) y off instead of the true intrinsic profile y(θ). We follow the approach presented in Bellagamba et al (2018) and Giocoli et al (2021) by dividing the cluster population into a fraction f off , which is affected by miscentering, and a fraction 1 − f off , whose true cluster positions coincide with the nominal ones. The observed resulting miscentered profile y msc is then…”

“…Most of these studies have employed a limited set of well-characterized and high-significance clusters in order to measure the cluster pressure profile (Arnaud et al 2010;Planck Collaboration et al 2013;Sayers et al 2016;He et al 2021;Pointecouteau et al 2021). A substantially different approach was adopted in Gong et al (2019;hereafter, G19), with the UPP parameters being fitted over a stack of a large number (∼10 5 ) of regions surrounding luminous red galaxies (LRGs) at z  0.5, assuming the latter to be good tracers of massive dark matter halos. This type of work forgoes the profile reconstruction for individual objects, focusing instead on the mean ICM properties of an extended sample.…”

AMICO galaxy clusters in KiDS-DR3: Constraints on cosmological parameters and on the normalisation of the mass-richness relation from clustering

“…Currently, the most reliable mass measurements are provided by weak gravitational lensing (e.g. Bardeau et al 2007;Okabe et al 2010;Hoekstra et al 2012;Melchior et al 2015;Schrabback et al 2018;Stern et al 2019;Sereno et al 2017;Giocoli et al 2021;Ingoglia et al 2022). Combining this information with the estimate of some optical cluster properties, such as the richness, it is possible to derive cluster mass-observable scaling relations.…”