A Blind Estimation of the Angular Power Spectrum of Cmb Anisotropy from Wmap
نویسندگان
چکیده
Accurate measurements of angular power spectrum of Cosmic Microwave Background (CMB) radiation has lead to marked improvement in the estimates of different cosmological parameters. This has required removal of foreground contamination as well as detector noise bias with reliability and precision. We present the estimation of CMB angular power spectrum from the multi-frequency observations of WMAP using a novel model-independent method. The primary product of WMAP are the observations of CMB in 10 independent difference assemblies (DA) that have uncorrelated noise. Our method utilizes maximum information available within WMAP data by linearly combining all the DA maps to remove foregrounds and estimating the power spectrum from cross power spectra of clean maps with independent noise. We compute 24 cross power spectra which are the basis of the final power spectrum. The binned average power matches with WMAP team’s published power spectrum closely. A small systematic difference at large multipoles is accounted for by the correction for the expected residual power from unresolved point sources. The correction is small and significantly tempered. Previous estimates have depended on foreground templates built using extraneous observational input. This is the first demonstration that the CMB angular spectrum can be reliably estimated with precision from a self contained analysis of the WMAP data. Subject headings: cosmic microwave background cosmology: observations
منابع مشابه
A Blind Estimation of the Power Spectrum of Cmb Anisotropy from Wmap
The angular power spectrum of Cosmic Microwave Background (CMB) radiation has proved to be an excellent observation to measure different cosmological parameters. In order to extract cosmological parameters precisely we need to remove foreground contamination as well as detector noise bias. In this paper we present a framework to extract CMB angular power spectrum from the multi-frequency observ...
متن کاملAngular power spectrum of CMB anisotropy from WMAP
The remarkable improvement in the estimates of different cosmological parameters in recent years has been largely spearheaded by accurate measurements of the angular power spectrum of Cosmic Microwave Background (CMB) radiation. This has required removal of foreground contamination as well as detector noise bias with reliability and precision. Recently, a novel model-independent method for the ...
متن کاملar X iv : a st ro - p h / 03 05 25 4 v 1 14 M ay 2 00 3 The shape of the CMB power spectrum
The recent WMAP data represents a milestone in cosmology and helps constrain cosmological parameters with unprecedented accuracy. In this work we combine the WMAP data with previous CMB anisotropy measurements at smaller angular scales to characterize the shape of the CMB anisotropy power spectrum. We carry out a phenomenological analysis of the data. By allowing non-physical shapes of the powe...
متن کاملStatistical isotropy of CMB anisotropy from WMAP
The statistical expectation values of the temperature fluctuations of cosmic microwave background (CMB) are assumed to be preserved under rotations of the sky. We investigate the statistical isotropy of the CMB anisotropy maps recently measured by the Wilkinson Microwave Anisotropy Probe (WMAP) using bipolar spherical harmonic power spectrum proposed in Hajian & Souradeep 2003. The Bipolar Powe...
متن کاملCosmological reionization after WMAP: perspectives from PLANCK and future CMB missions
The WMAP first year detection of a high redshift reionization through its imprints on CMB anisotropy T and TE mode angular power spectra calls for a better comprehension of the universe ionization and thermal history after the standard recombination. Different reionization mechanisms predict different signatures in the CMB, both in temperature and polarization anisotropies and in spectral disto...
متن کامل