Theoretical estimates of integrated Sachs–Wolfe effect detection through the Australian Square Kilometre Array Pathfinder’s Evolutionary Map of the Universe (ASKAP- EMU) survey, with confusion, position uncertainty, shot noise, and signal-to-noise ratio analysis

Abstract

Detection of the late-time integrated Sachs–Wolfe (ISW) effect is an active area of study related to large-scale structures (LSSs). The ISW effect can be studied by observing the non-zero cross-correlation between cosmic microwave background (CMB) anisotropies with tracers of mass field, such as galaxy survey data. We study this effect by cross-correlating the CMB data and related cosmological parameters, as delineated by the Wilkinson Microwave Anisotropy Probe (WMAP), with the upcoming Evolutionary Map of the Universe (EMU) survey planned for the Australian Square Kilometre Array Pathfinder (ASKAP). ASKAP-EMU will conduct a deep radio continuum survey with a root-mean-square (rms) flux of 10 μJy per beam (1 Jy = 10–26 Wm–2Hz–1). The survey will cover the entire southern sky, extending to +30° declination. To infer the expected redshift distribution (dN/dz) and differential source count (S) that can be extracted from the galaxies surveyed via EMU, we use data from the S-cubed simulation of extragalactic radio continuum sources (S3-SEX) for the Square Kilometre Array Design Studies (SKADS). We also calculate various parameters including galaxy survey shot noise, root mean square confusion uncertainty, and position uncertainty for the survey, which can help in understanding the accuracy of the survey results and in performing the data analysis. We also discuss signal-to-noise ratios over a range of maximum redshifts and maximum multipole values with some discussion on constraints over dark energy density parameter (ΩΛ) and baryonic matter density parameter (Ωb).