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Title: A FOREGROUND-CLEANED COSMIC MICROWAVE BACKGROUND MAP FROM NON-GAUSSIANITY MEASUREMENT

Abstract

In this Letter, we present a new method to estimate a foreground-cleaned cosmic microwave background (CMB) map at a resolution of 1{sup 0} by minimizing the non-Gaussian properties of the cleaned map which arise dominantly due to diffuse foreground emission components from the Milky Way. We employ simple kurtosis statistic as the measure of non-Gaussian properties and perform a linear combination of five frequency maps provided by the Wilkinson Microwave Anisotropy Probe (WMAP) in its seven-year data release in such a way that the cleaned map has a minimum kurtosis which leads to a non-Gaussianity-minimized, foreground-cleaned CMB map. We validate the method by performing Monte Carlo simulations. To minimize any residual foreground contamination from the cleaned map we flag out the region near the galactic plane based upon results from simulations. Outside the masked region our new estimate of the CMB map matches well with the WMAP's Internal Linear Combination (ILC) map. A simple pseudo-C{sub l} -based CMB TT power spectrum derived from the non-Gaussianity minimized map reproduces the earlier results of WMAP's power spectrum. An important advantage of the method is that it does not introduce any negative bias in angular power spectrum in the low multipole regime, unlikemore » usual ILC method. Comparing our results with the previously published results we argue that CMB results are robust with respect to specific foreground removal algorithms employed.« less

Authors:
 [1]
  1. Physics Department, Indian Institute of Science Education and Research Bhopal, Bhopal, MP 462023 (India)
Publication Date:
OSTI Identifier:
21565423
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal Letters
Additional Journal Information:
Journal Volume: 739; Journal Issue: 2; Other Information: DOI: 10.1088/2041-8205/739/2/L56; Journal ID: ISSN 2041-8205
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COMPUTERIZED SIMULATION; EMISSION; MAPS; MILKY WAY; MONTE CARLO METHOD; RELICT RADIATION; STATISTICS; CALCULATION METHODS; ELECTROMAGNETIC RADIATION; GALAXIES; MATHEMATICS; MICROWAVE RADIATION; RADIATIONS; SIMULATION

Citation Formats

Saha, Rajib. A FOREGROUND-CLEANED COSMIC MICROWAVE BACKGROUND MAP FROM NON-GAUSSIANITY MEASUREMENT. United States: N. p., 2011. Web. doi:10.1088/2041-8205/739/2/L56.
Saha, Rajib. A FOREGROUND-CLEANED COSMIC MICROWAVE BACKGROUND MAP FROM NON-GAUSSIANITY MEASUREMENT. United States. doi:10.1088/2041-8205/739/2/L56.
Saha, Rajib. Sat . "A FOREGROUND-CLEANED COSMIC MICROWAVE BACKGROUND MAP FROM NON-GAUSSIANITY MEASUREMENT". United States. doi:10.1088/2041-8205/739/2/L56.
@article{osti_21565423,
title = {A FOREGROUND-CLEANED COSMIC MICROWAVE BACKGROUND MAP FROM NON-GAUSSIANITY MEASUREMENT},
author = {Saha, Rajib},
abstractNote = {In this Letter, we present a new method to estimate a foreground-cleaned cosmic microwave background (CMB) map at a resolution of 1{sup 0} by minimizing the non-Gaussian properties of the cleaned map which arise dominantly due to diffuse foreground emission components from the Milky Way. We employ simple kurtosis statistic as the measure of non-Gaussian properties and perform a linear combination of five frequency maps provided by the Wilkinson Microwave Anisotropy Probe (WMAP) in its seven-year data release in such a way that the cleaned map has a minimum kurtosis which leads to a non-Gaussianity-minimized, foreground-cleaned CMB map. We validate the method by performing Monte Carlo simulations. To minimize any residual foreground contamination from the cleaned map we flag out the region near the galactic plane based upon results from simulations. Outside the masked region our new estimate of the CMB map matches well with the WMAP's Internal Linear Combination (ILC) map. A simple pseudo-C{sub l} -based CMB TT power spectrum derived from the non-Gaussianity minimized map reproduces the earlier results of WMAP's power spectrum. An important advantage of the method is that it does not introduce any negative bias in angular power spectrum in the low multipole regime, unlike usual ILC method. Comparing our results with the previously published results we argue that CMB results are robust with respect to specific foreground removal algorithms employed.},
doi = {10.1088/2041-8205/739/2/L56},
journal = {Astrophysical Journal Letters},
issn = {2041-8205},
number = 2,
volume = 739,
place = {United States},
year = {2011},
month = {10}
}