B-mode constraints from Planck low multipole polarisation data

Abstract

We present constraints on primordial B modes from large angular scale cosmic microwave background polarisation anisotropies measured with the Planck satellite. To remove Galactic polarised foregrounds, we use a Bayesian parametric component separation method, modelling synchrotron radiation as a power law and thermal dust emission as a modified blackbody. This method propagates uncertainties from the foreground cleaning into the noise covariance matrices of the maps. We construct two likelihoods: (i) a semi-analytical cross-spectrum-based likelihood-approximation scheme (momento) and (ii) an exact polarisation-only pixel-based likelihood (pixlike). Since momento is based on cross-spectra it is statistically less powerful than pixlike, but is less sensitive to systematic errors correlated across frequencies. Both likelihoods give a tensor-to-scalar ratio, r, that is consistent with zero from low multipole (2 <= ell < 30) Planck polarisation data. From full-mission maps we obtain r_0.05<0.274, at 95 per cent confidence, at a pivot scale of k = 0.05 Mpc^-1, using pixlike. momento gives a qualitatively similar but weaker 95 per cent confidence limit of r_0.05<0.408.

arXiv comment10 pages, 7 figures

References in corpus (23)

• HEALPix -- a Framework for High Resolution Discretization, and Fast Analysis of Data Distributed on the Sphere
• The Simons Observatory: Science goals and forecasts
• Three Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Polarization Analysis
• Planck 2018 results. V. CMB power spectra and likelihoods
• Signature of Gravity Waves in Polarization of the Microwave Background
• BICEP / Keck XIII: Improved Constraints on Primordial Gravitational Waves using Planck, WMAP, and BICEP/Keck Observations through the 2018 Observing Season
• A Probe of Primordial Gravity Waves and Vorticity
• Planck intermediate results. XLVI. Reduction of large-scale systematic effects in HFI polarization maps and estimation of the reionization optical depth
• Planck intermediate results. LVII. Joint Planck LFI and HFI data processing
• CMB-S4: Forecasting Constraints on Primordial Gravitational Waves
• Improved limits on the tensor-to-scalar ratio using BICEP and Planck
• Likelihood Analysis of CMB Temperature and Polarization Power Spectra
• The Atacama Cosmology Telescope: The polarization-sensitive ACTPol instrument
• How to measure CMB polarization power spectra without losing information
• CMB mapping experiments: a designer's guide
• Planck constraints on the tensor-to-scalar ratio
• SPTpol: an instrument for CMB polarization measurements with the South Pole Telescope
• Planck 2018 results. II. Low Frequency Instrument data processing
• Updated design of the CMB polarization experiment satellite LiteBIRD
• SRoll2: an improved mapmaking approach to reduce large-scale systematic effects in the Planck High Frequency Instrument legacy maps
• Inference of the optical depth to reionization from low multipole temperature and polarisation Planck data
• B-mode Detection with an Extended Planck Mission
• BICEP's acceleration

Cited by in corpus (4)

• LiteBIRD Science Goals and Forecasts. A Case Study of the Origin of Primordial Gravitational Waves using Large-Scale CMB Polarization
• Cosmology from Planck CMB Lensing and DESI DR1 Quasar Tomography
• Impact of Galactic dust non-Gaussianity on searches for B-modes from inflation
• Accurate and efficient likelihood modeling for large-scale CMB data