Abstract Details
| Name: Nikhel Gupta Affiliation: Ludwig Maximilians University, Munich, Germany Conference ID: ASI2017_1091 Title : Observations and Simulations of Galaxy Clusters: Cluster Radio Galaxies and their Implications on SZE Signal, Simulated Pressure Profiles and SZE Mass Authors and Co-Authors : N. Gupta⋆1,2,3 , A. Saro1,2 , J. J. Mohr1,2,3 , B. A. Benson4,5,6 , S. Bocquet5,7,1,2 , R. Capasso1,2 , J. E. Carlstrom4,5,7,12,13 , I. Chiu1,2 , T. M. Crawford4,5 , T. de Haan8,9 , J. P. Dietrich1,2 , C. Gangkofner1,2 , W. L. Holzapfel8 , M. McDonald10 , D. Rapetti1,2 , C. L. Reichardt11 , K. Dolag1,2,3 1 Faculty of Physics, Ludwig-Maximilians-Universit¨at, Scheinerstr. 1, 81679 Munich, Germany 2 Excellence Cluster Universe, Boltzmannstr. 2, 85748 Garching, Germany 3 Max Planck Institute for Extraterrestrial Physics, Giessenbachstr. 85748 Garching, Germany 4 Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 5 Kavli Institute for Cosmological Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 6 Center for Particle Astrophysics, Fermi National Accelerator Laboratory, Batavia, IL, USA 60510 7 Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL, USA 60439 8 Department of Physics, University of California, Berkeley, CA 94720 9 Department of Physics,McGill University, 3600 Rue University, Montreal, Quebec H3A 2T8, Canada 10 Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 11 School of Physics, University of Melbourne, Parkville, VIC 3010, Australia 12 Enrico Fermi Institute, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 13 Department of Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 Abstract Type : Oral Abstract Category : General Relativity and Cosmology Abstract : The discrepancy between cosmology derived from Cosmic Microwave Background (CMB) and Sunyaev-Zel’dovich Effect (SZE) selected galaxy clusters has gathered a lot of attention in recent years. The incompleteness of cluster sample and/or discrepancy in cluster masses can be the reason for this difference from two experiments. We study the overdensity of point sources in the direction of X-ray-selected galaxy clusters from the Meta-Catalog of X-ray detected Clusters of galaxies (MCXC; ⟨z⟩ = 0.14) at South Pole Telescope (SPT) and Sydney University Molonglo Sky Survey (SUMSS) frequencies. Flux densities at 95, 150 and 220 GHz are extracted from the 2500 deg^2 SPT-SZ survey maps at the locations of SUMSS sources, producing a multi-frequency catalog of radio galaxies. In the direction of massive galaxy clusters, the radio galaxy flux densities at 95 and 150 GHz are biased low by the cluster SZE signal, which is negative at these frequencies. We employ a cluster SZE model to remove the expected flux bias and then study these corrected source catalogs. We use the 150 GHz LF to estimate the impact of cluster radio galaxies on an SPT-SZ like survey. If we assume there is no redshift evolution in the radio galaxy LF then 1.8 ± 0.7 percent of the clusters with detection significance ξ ≥ 4.5 would be lost from the sample, that doesn't explain the cosmological discrepancy. Improved constraints on the evolution of the cluster radio galaxy LF require a larger cluster sample extending to higher redshift. I will present preliminary results using redMaPPer cluster catalog observed in Dark Energy Survey (DES). In an another work, we study clusters’ thermal-Sunyaev-Zel’dovich effect (SZE) from Magneticum Pathfinder hydrodynamical simulations. We examine the thermal intracluster medium (ICM) pressure profiles for galaxy clusters (M500c > 1.4 × 10^14 M⊙) out to z = 2, study the variations in shape of profiles and look for deviations from self similar evolution. We show that the thermal ICM pressure is lower than the effective pressure deduced from the approximation of hydrostatic equilibrium by 20 percent at R500c and correcting this brings cluster cosmology closer to that derived from CMB. Further, we study the Y-mass relation, confirming previous results showing that the scatter (spherical) in the relation is small (σ_{ln Y} ≃ 0.087). In addition, we examine the impact of cluster triaxiality and large scale structure along the line of sight by measuring the cylindrical signal in redshift slices and the full light cone, respectively. |