Revisiting the oscillations in the CMB angular power spectra at $\ell\sim120$ in the Planck2015 data

Abstract

While the observed nearly scale-invariant initial power spectrum is regarded as one of the favorable evidence of the standard inflationary cosmology, precision observations of the Cosmic Microwave Background (CMB) anisotropies also suggest possible existence of nontrivial features such as those observed around multipoles $\ell\sim120$ by WMAP. Here, we examine the Planck data and investigate the effects of these features on the cosmological parameter estimation performing the Markov-Chain Monte-Carlo (MCMC) analysis. We find that the features exist in the Planck data at the same position as the case of the WMAP data but they do not affect the cosmological parameter estimation significantly.