The High Redshift Integrated Sachs-Wolfe Effect

Abstract

In this paper we rely on the quasar (QSO) catalog of the Sloan Digital Sky Survey Data Release Six (SDSS DR6) of about one million photometrically selected QSOs to compute the Integrated Sachs-Wolfe (ISW) effect at high redshift, aiming at constraining the behavior of the expansion rate and thus the behaviour of dark energy at those epochs. This unique sample significantly extends previous catalogs to higher redshifts while retaining high efficiency in the selection algorithm. We compute the auto-correlation function (ACF) of QSO number density from which we extract the bias and the stellar contamination. We then calculate the cross-correlation function (CCF) between QSO number density and Cosmic Microwave Background (CMB) temperature fluctuations in different subsamples: at high z>1.5 and low z<1.5 redshifts and for two different choices of QSO in a conservative and in a more speculative analysis. We find an overall evidence for a cross-correlation different from zero at the 2.7σlevel, while this evidence drops to 1.5σat z>1.5. We focus on the capabilities of the ISW to constrain the behaviour of the dark energy component at high redshift both in the \LambdaCDM and Early Dark Energy cosmologies, when the dark energy is substantially unconstrained by observations. At present, the inclusion of the ISW data results in a poor improvement compared to the obtained constraints from other cosmological datasets. We study the capabilities of future high-redshift QSO survey and find that the ISW signal can improve the constraints on the most important cosmological parameters derived from Planck CMB data, including the high redshift dark energy abundance, by a factor \sim 1.5.

20 pages, 18 figures, and 7 tables

References in corpus (22)

• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Data Processing, Sky Maps, and Basic Results
• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Likelihoods and Parameters from the WMAP data
• Improved Cosmological Constraints from New, Old and Combined Supernova Datasets
• Measuring the Baryon Acoustic Oscillation scale using the SDSS and 2dFGRS
• Clustering of High Redshift ($z\ge 2.9$) Quasars from the Sloan Digital Sky Survey
• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Angular Power Spectra
• Correlation of CMB with large-scale structure: I. ISW Tomography and Cosmological Implications
• Combined analysis of the integrated Sachs-Wolfe effect and cosmological implications
• Correlation of CMB with large-scale structure: II. Weak lensing
• The Wilkinson Microwave Anisotropy Probe (WMAP) Source Catalog
• Constraining dark energy with cross-correlated CMB and Large Scale Structure data
• A reassessment of the evidence of the Integrated Sachs-Wolfe effect through the WMAP-NVSS correlation
• BigBOSS: The Ground-Based Stage IV Dark Energy Experiment
• Determining Cosmological Parameters with Latest Observational Data
• Early Dark Energy at High Redshifts: Status and Perspectives
• Probing Dark Energy at Galactic and Cluster Scales
• Constraining neutrino masses with the ISW-galaxy correlation function
• Optimal ISW detection and joint likelihood for cosmological parameter estimation
• Lenses in the forest: cross-correlation of the Lyman-alpha flux with CMB lensing
• Cosmic reionization in a dynamic quintessence cosmology
• The Effect of Redshift Distortions on the Integrated Sachs-Wolfe Signal