An Improved Diffuse Foreground Subtraction by ILC method: CMB Map and Angular Power Spectrum using Planck and WMAP Observations

Abstract

We report an improved technique for diffuse foreground minimization from Cosmic Microwave Background (CMB) maps using a new multi-phase iterative internal-linear-combination (ILC) approach in harmonic space. The new procedure consists of two phases. In phase 1, a diffuse foreground cleaned map is obtained by performing a usual ILC operation in the harmonic space in a single iteration over the desired portion of the sky. In phase 2, we obtain the final foreground cleaned map using an iterative ILC approach also in the harmonic space, however, now, during each iteration of foreground minimization, some of the regions of the sky that are not being cleaned in the current iteration, are replaced by the corresponding cleaned portions of the phase 1 cleaned map. The new ILC method nullifies a foreground leakage signal that is otherwise inevitably present in the old and usual harmonic space iterative ILC method. The new method is flexible to handle input frequency maps, irrespective of whether or not they initially have the same instrumental and pixel resolution, by bringing them to a common and maximum possible beam and pixel resolution at the beginning of the analysis. This dramatically reduces data redundancy and hence memory usage and computational cost. During the ILC weight calculation it avoids any need to deconvolve partial sky spherical harmonic coefficients by the beam and pixel window functions, which in strict mathematical sense, is not well-defined for azimuthally symmetric window functions. Using WMAP 9-year and Planck-2015 published frequency maps we obtain a pair of foreground cleaned CMB maps and CMB angular power spectrum. Our power spectrum match well with Planck-2015 results, with some difference. Finally, we show that the weights for ILC foreground minimization have an intrinsic characteristic that it tends to produce a statistically isotropic CMB map as well.

arXiv comment17 pages, 17 figures

References in corpus (56)

• Planck 2015 results. XIII. Cosmological parameters
• Planck 2013 results. XVI. Cosmological parameters
• HEALPix -- a Framework for High Resolution Discretization, and Fast Analysis of Data Distributed on the Sphere
• Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Parameter Results
• Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Final Maps and Results
• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Implications for Inflation
• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Foreground Emission
• Three-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Temperature Analysis
• MASTER of the CMB Anisotropy Power Spectrum: A Fast Method for Statistical Analysis of Large and Complex CMB Data Sets
• Asymmetries in the CMB anisotropy field
• Planck 2015 results. XI. CMB power spectra, likelihoods, and robustness of parameters
• A high resolution foreground cleaned CMB map from WMAP
• Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Galactic Foreground Emission
• Cosmic Topology
• Planck 2015 results. XVI. Isotropy and statistics of the CMB
• A Measurement of the Cosmic Microwave Background Damping Tail from the 2500-square-degree SPT-SZ survey
• A method for subtracting foregrounds from multi-frequency CMB sky maps
• Multipole Vectors--a new representation of the CMB sky and evidence for statistical anisotropy or non-Gaussianity at 2<=l<=8
• Joint Bayesian component separation and CMB power spectrum estimation
• A full sky, low foreground, high resolution CMB map from WMAP
• Hemispherical power asymmetry in the three-year Wilkinson Microwave Anisotropy Probe sky maps
• Constraints on Cosmology from the Cosmic Microwave Background Power Spectrum of the 2500 ${\mathrm{deg}}^2$ SPT-SZ Survey
• Planck 2015 results. IX. Diffuse component separation: CMB maps
• On Foreground Removal from the Wilkinson Microwave Anisotropy Probe Data by an Internal Linear Combination Method: Limitations and Implications
• Planck 2015 results. VIII. High Frequency Instrument data processing: Calibration and maps
• Constraining the Topology of the Universe
• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Galactic Foreground Emission
• CMB and SZ effect separation with Constrained Internal Linear Combinations
• Measuring Statistical isotropy of the CMB anisotropy
• Topology and the Cosmic Microwave Background
• Foregrounds and CMB Experiments: I. Semi-analytical estimates of contamination
• Polarization of the Microwave Background due to Primordial Gravitational Waves
• A needlet ILC analysis of WMAP 7-year data: estimation of CMB temperature map and power spectrum
• CMB polarization as a direct test of Inflation
• Cosmological Parameters from Pre-Planck CMB Measurements
• Planck 2015 results. XVIII. Background geometry & topology
• Statistical Isotropy of the Wilkinson Microwave Anisotropy Probe Data: A Bipolar Power Spectrum Analysis
• A re-analysis of the three-year WMAP temperature power spectrum and likelihood
• Testing Global Isotropy of Three-Year Wilkinson Microwave Anisotropy Probe (WMAP) Data: Temperature Analysis
• A needlet ILC analysis of WMAP 9-year polarisation data: CMB polarisation power spectra
• Planck 2015 results. II. Low Frequency Instrument data processing
• Testing Isotropy of Cosmic Microwave Background Radiation
• Wiener Filtering of the COBE DMR Data
• A blind estimation of the power spectrum of CMB anisotropy from WMAP
• CMB anisotropy power spectrum using linear combinations of WMAP maps
• The Status of Cosmic Topology after Planck Data
• The joint large-scale foreground-CMB posteriors of the 3-year WMAP data
• Extracting cosmic microwave background polarisation from satellite astrophysical maps
• CMB map derived from the WMAP data through Harmonic Internal Linear Combination
• CMB polarization map derived from the WMAP 5 year data through Harmonic Internal Linear Combination
• SILC: a new Planck Internal Linear Combination CMB temperature map using directional wavelets
• A Foreground Cleaned CMB Map from Non-Gaussianity Measurement
• Constraining the topology of the Universe using the polarised CMB maps
• Spin-SILC: CMB polarisation component separation with spin wavelets
• CMB Polarization and Temperature Power Spectra Estimation using Linear Combination of WMAP 5-year Maps
• A Perturbative Analysis of Synchrotron Spectral Index Variation over Microwave Sky

Cited by in corpus (9)

• Explicit Bayesian treatment of unknown foreground contaminations in galaxy surveys
• Bayesian power-spectrum inference with foreground and target contamination treatment
• A Global ILC Approach in Pixel Space over Large Angular Scales of the Sky using CMB Covariance Matrix
• Recovering Cosmic Microwave Background Polarization Signals with Machine Learning
• Data driven foreground clustering approach to component separation in multifrequency CMB experiments: A new Planck CMB map
• An Accurate Reconstruction of CMB E Mode Signal over Large Angular Scales using Prior Information of CMB Covariance Matrix in ILC Algorithm
• On the Impact of Random Residual Calibration Error on the Gibbs ILC Estimates over Large Angular Scales
• A Partial-Sky Gibbs ILC Approach for the Estimation of CMB Posterior over Large Angular Scales of the Sky
• The CMB angular power spectrum via component separation: a study on Planck data