CMB Polarization and Temperature Power Spectra Using WMAP 5 Year Maps
Abstract
We estimate CMB polarization and temperature power spectrum using WMAP5-year foreground contaminated maps. The power spectrum estimation methoddoes not utilize the diffuse foreground templates nor the detector noisemodel. The method essentially consists of two steps, (i) removal ofdiffuse foregrounds contamination by making linear combination ofindividual maps and (ii) cross-correlation of foreground cleaned maps tominimize detector noise bias. For temperature power spectrum we alsoestimate and subtract residual unresolved point source contamination inthe cross-power spectrum by using WMAP’s point source model. Our TT, TEand EE power spectra are in good agreement with the published results ofthe WMAP science team. We perform detailed numerical simulations to testfor bias in our procedure. We find that the bias is relatively small forthe TT and TE power spectrum. A negative bias at low l in TT powersepctrum has been pointed in an earlier publication. We find that thenegative bias corrected quadrupole power (l(l+1)C_l/(2*pi)) is 532 microK^2, approximately 2.5 times the WMAP’s result (313.4 micro K^2).
