Day 1003

Monday.


1511.01919
LoCuSS: testing hydrostatic equilibrium in galaxy clusters
Smith, et al

Test the assumption of hydrostatic equilibrium in an X-ray luminosity selected sample of 50 galaxy clusters at 0.15<z<0.3 from LoCuSS.  The WL measurements of M500 control systematic biases to sub-4%, and the hydrostatic measurements of the same achieve excellent agreement between XMM-Newton and Chandra.  The mean ratio of X-ray to lensing mass for these 50 clusters is beta_X=0.95±0.05, and for the 44 clusters also detected by Planck, the mean ratio of Planck mass estimate to LoCuSS lensing mass is beta_P=0.95±0.04.  Based on a careful like-for-like analysis, find that LoCuSS, CCCP, and WtG agree on beta_P~0.9-0.95 at 0.15<z<0.3.  This small level of hydrostatic bias disagrees at ~5sigma with the level required to reconcile planck cosmology results from the CMB and galaxy cluster counts.


1511.01983
The clustering and halo occupation distribution of Lyman-break galaxies at z~4
Park et al

Compare GALFORM SAM angular correlation function (ACF) of galaxies with XDF and CANDELS galaxies; find that the predicted ACFs are in good agreement with the measured ones, but the predicted ACFs show a weaker dependence on luminosity than is inferred from observations.  Show act the fraction of satellite LBGs is important for determining the amplitude of the ACF on small scales.  Find that central lyman-break galaxies (LBGs) at z~4 predominantly reside in haloes of mass 1e11-12 Msun/h and that satellites reside in larger haloes of mass 1e12-13 Msun/h.  The model predicts fewer bright satellite LBGs at z~4 than are inferred from clustering measurements.  Investigate the effect of the photometric scatter in the observations on the ACF predictions.  Find the the observational uncertainty in the galaxy luminosity reduces the clustering amplitude, and that this effect increases toward faint galaxies, particularly on small scales.  To compare properties of model LBGs with those of observations, this uncertainty must be considered.  By analyzing the HOD, find evidence that AGN feedback affects the HOD of central LBGs in massive haloes.