Program: GS-2009B-Q-2

Title:Mass calibration and gas physics for ACT SZ clusters
PI:Luis Felipe Barrientos
Co-I(s): Leopoldo Infante, John P. Hughes, Jean-Baptiste Juin, Felipe Menanteau, Harold Francke, Paula Aguirre

Abstract

The Atacama Cosmology Telescope (ACT) has begun to survey the southern sky at submm wavelengths covering ~400 sq deg over six months during 2008, and new observations are scheduled for 2009. This project will set constraints on the equation of state of the universe (represented by w) by studying the correlation function of the anisotropies in the CMB. In the process of characterizing the anisotropies, there will be a natural selection of other sources such as galaxy clusters and submm galaxies. The clear signature of the Sunyaev-Zel'dovich effect will be used to produce a unique sample of galaxy clusters defined only by a lower mass limit and essentially independent of distance. In this proposal we plan to complete a program started last semester for obtaining deep imaging and MOS spectroscopy for a sample of 4 massive clusters (>1e15 Msun) detected in the optical present in the submm map area, and determine their masses by dynamics and weak lensing. The overall sample (of 30-40 clusters) will be used to calibrate the Y-mass (Y represents the SZ signature) scaling relation for using the whole sample of clusters for setting constraints on w independently from the correlation funtion analysis. This sample will also allows us to start studying the cluster gas physics responsible for the the SZ signature.

Publications using this program's data