Day 1070

Thursday.

1603.06953

Weak lensing measurement of the mass--richness relation of SDSS redMaPPer Clusters

Simet, et al

Perform a measurement of the mass-richness relation of the redMaPPer galaxy cluster catalogue using WL data from SDSS.  Characterize a broad range of systematic uncertainties, including shear calibration errors, photo-z biases, dilution by member galaxies, source obscuration, magnification bias, incorrect assumptions about cluster mass profiles, cluster centering, halo triaxiality, and projection effects.  Also compare measurements of the lensing signal from two independently-produced shear and photo-z catalogues to characterize systematic error in the lensing signal itself.  Using a sample of 5,570 clusters from 0.1<=z<=0.33, the normalization of the power-law mass vs lambda relation is log10[M200m/(Msun/h)] = 14.344±0.021 (stat) ± 0.023 (sys) at a richness lambda=40, a 7% calibration uncertainty, with a power-law index of 1.33±0.09 (1sigma).  The detailed systematics characterization in this work renders it the definitive WL mass calibration for SDSS redMaPPer clusters at this time.

1603.06955

Cosmic web type dependence of halo clustering

Fisher, Faltenbecher

Use the Millennium sim to show that halo clustering varies significantly with cosmic web type.  Haloes are classified as node, filament, sheet and void halos based on the eigenvalue decomposition of the velocity shear tensor.  This classification allows examination of the clustering of halos as a function of web type in different mass ranges.  Find that node haloes show positive bias for all mass ranges probed, even from 1e11 and 1e12 Msun/h mass bins where the clustering of the entire halo sample is anti-biased.  In all mass bins filament halos show negligible bias, whereas void and sheet halos are anti-biased.  The zero-crossing of the void and sheet correlation functions occur at much smaller scales Mpc/h when compared to the same correlation functions for the entire halo sample.  The realists suggest that the mass dependence of halo clustering is rooted in the composition of web types in the mass bin.  The substantial fraction of node type halos for halo masses 2e13 Msun/h leads to positive bias.  Filament type halos prevail at intermediate masses, 1e12-13 Msun/h, resulting in unbiased clustering.  The large contribution of sheet type halos at low halo masses 1e12 Msun/h generates anti-biasing.