ﻻ يوجد ملخص باللغة العربية
We perform a comparison of WMAP 9-year (WMAP9) and Planck 2015 cosmic microwave background (CMB) temperature power spectra across multipoles $30leqellleq1200$. We generate simulations to estimate the correlation between the two datasets due to cosmic variance from observing the same sky. We find that their spectra are consistent within $1sigma$. While we do not implement the optimal $C^{-1}$ estimator on WMAP maps as in the WMAP9 analysis, we demonstrate that the change of pixel weighting only shifts our results at most at the $0.66sigma$ level. We also show that changing the fiducial power spectrum for simulations only impacts the comparison at around $0.1sigma$ level. We exclude $ell<30$ both because WMAP9 data were included in the Planck 2015 $ell<30$ analysis, and because the cosmic variance uncertainty on these scales is large enough that any remaining systematic difference between the experiments is extremely unlikely to affect cosmological constraints. The consistency shown in our analysis provides high confidence in both the WMAP9 temperature power spectrum and the overlapping multipole region of Planck 2015s, virtually independent of any assumed cosmological model. Our results indicate that cosmological model differences between Planck and WMAP do not arise from measurement differences, but from the high multipoles not measured by WMAP.
(Abridged) We present the angular power spectra derived from the 7-year maps and discuss the cosmological conclusions that can be inferred from WMAP data alone. The third acoustic peak in the TT spectrum is now well measured by WMAP. In the context o
This paper presents the Planck 2015 likelihoods, statistical descriptions of the 2-point correlations of CMB data, using the hybrid approach employed previously: pixel-based at $ell<30$ and a Gaussian approximation to the distribution of spectra at h
We examine the consistency of WMAP9 and Planck data. We compare sky maps, power spectra, and inferred LCDM cosmological parameters. Residual dipoles are seen in the WMAP and Planck sky map differences, but are consistent within the uncertainties and
A well-tested and validated Gibbs sampling code, that performs component separation and CMB power spectrum estimation, was applied to the {it WMAP} 5-yr data. Using a simple model consisting of CMB, noise, monopoles and dipoles, a ``per pixel low-fre
(Abridged)Motivated by the recent results of Hansen et al. (2008) concerning a noticeable hemispherical power asymmetry in the WMAP data on small angular scales, we revisit the dipole modulated signal model introduced by Gordon et al. (2005). This mo