The S-PASS view of polarized Galactic Synchrotron at 2.3 GHz as a contaminant to CMB observations

Abstract

We analyze the Southern Sky emission in linear polarization at 2.3 GHz as observed by the S-band Polarization All Sky Survey S-PASS. Our purpose is to study the properties of the diffuse Galactic polarized synchrotron as a contaminant to CMB B-mode observations. We study the angular distribution of the S-PASS signal at intermediate and high Galactic latitudes by means of angular power spectra. Power spectra, show a decay of the spectral amplitude as a function of multipole for \ell<200, typical of the diffuse emission. Spectra can be approximated by a power law C_{\ell}\propto\ell^{alpha}, with alpha~-3, and characterized by a B-to-E ratio of ~0.5. We study the synchrotron SED in polarization by computing power spectra of the low frequency WMAP and Planck maps. Results show that the SED, in the frequency range 2.3-33 GHz, is compatible with a power law with beta_s=-3.22\pm0.08. Combining S-PASS polarization maps with those coming from WMAP and Planck we derived a map of the synchrotron spectral index at angular resolution of 2° on about 30% of the sky. The recovered distribution peaks at the value around -3.2. We also measure a significant spatial correlation between synchrotron and thermal dust signals, as traced by the Planck 353 GHz channel. This correlation reaches about 40% on the larger angular scales, decaying considerably at the degree scales. Finally, we use the S-PASS maps to assess the polarized synchrotron contamination to CMB observations of the B-modes. Moreover, by combining S-PASS data with Planck 353 GHz observations, we recover a map of the minimum level of total polarized foreground contamination to B-modes, finding that there is no region of the sky, at any frequency, where this contamination lies below equivalent tenor-to-scalar ratio ~10^-3. This result confirms the importance of observing both high and low frequency foregrounds in CMB B-mode measurements.

arXiv commentaccepted for publication on A&A

References in corpus (38)

• Planck 2015 results. XIII. Cosmological parameters
• HEALPix -- a Framework for High Resolution Discretization, and Fast Analysis of Data Distributed on the Sphere
• Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Final Maps and Results
• An All-Sky Analysis of Polarization in the Microwave Background
• Statistics of Cosmic Microwave Background Polarization
• A Joint Analysis of BICEP2/Keck Array and Planck Data
• BICEP2 / Keck Array VI: Improved Constraints On Cosmology and Foregrounds When Adding 95 GHz Data From Keck Array
• Gravitational Lensing Effect on Cosmic Microwave Background Polarization
• A CMB Polarization Primer
• Detection of B-mode Polarization in the Cosmic Microwave Background with Data from the South Pole Telescope
• A Measurement of the Cosmic Microwave Background B-Mode Polarization Power Spectrum at Sub-Degree Scales with POLARBEAR
• Planck 2015 results. IX. Diffuse component separation: CMB maps
• The Python Sky Model: software for simulating the Galactic microwave sky
• Giant Magnetized Outflows from the Centre of the Milky Way
• Planck intermediate results. XXX. The angular power spectrum of polarized dust emission at intermediate and high Galactic latitudes
• The Atacama Cosmology Telescope: Two-Season ACTPol Spectra and Parameters
• Separation of anomalous and synchrotron emissions using WMAP polarization data
• Planck intermediate results. XXII. Frequency dependence of thermal emission from Galactic dust in intensity and polarization
• Xspect, estimation of the angular power spectrum by computing cross-power spectra with analytical error bars
• Three-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Foreground Polarization
• Robust forecasts on fundamental physics from the foreground-obscured, gravitationally-lensed CMB polarization
• A Measurement of the Cosmic Microwave Background $B$-Mode Polarization Power Spectrum at Sub-Degree Scales from 2 years of POLARBEAR Data
• Exploring Cosmic Origins with CORE: Survey requirements and mission design
• Measurements of Sub-degree B-mode Polarization in the Cosmic Microwave Background from 100 Square Degrees of SPTpol Data
• Spatial variations in the spectral index of polarized synchrotron emission in the 9 yr WMAP sky maps
• QUIJOTE Scientific Results. II. Polarisation Measurements of the Microwave Emission in the Galactic molecular complexes W43 and W47 and supernova remnant W44
• Planck intermediate results. L. Evidence for spatial variation of the polarized thermal dust spectral energy distribution and implications for CMB $B$-mode analysis
• Characterization of foreground emission at degree angular scale for CMB B-modes observations. Thermal Dust and Synchrotron signal from Planck and WMAP data
• Synchrotron Spectral Curvature from 22 MHz to 23 GHz
• Polarized galactic synchrotron and dust emission and their correlation
• The C-Band All-Sky Survey (C-BASS): Design and capabilities
• Forecasting performance of CMB experiments in the presence of complex foreground contaminations
• Power spectrum of the polarized diffuse Galactic radio emission
• Galactic interstellar filaments as probed by LOFAR and Planck
• Magnetic field disorder and Faraday effects on the polarization of extragalactic radio sources
• Planck intermediate results. LIV. The Planck Multi-frequency Catalogue of Non-thermal Sources
• A southern-sky total intensity source catalogue at 2.3 GHz from S-band Polarisation All-Sky Survey data
• No evidence for dust B-mode decorrelation in Planck data

Cited by in corpus (66)

• The Simons Observatory: Science goals and forecasts
• BICEP / Keck XIII: Improved Constraints on Primordial Gravitational Waves using Planck, WMAP, and BICEP/Keck Observations through the 2018 Observing Season
• Planck 2018 results. IV. Diffuse component separation
• CMB-S4: Forecasting Constraints on Primordial Gravitational Waves
• Planck 2018 results. XI. Polarized dust foregrounds
• Observational Constraints on the Physical Properties of Interstellar Dust in the Post-Planck Era
• S-band Polarization All Sky Survey (S-PASS): survey description and maps
• Peeling off foregrounds with the constrained moment ILC method to unveil primordial CMB $B$-modes
• A Measurement of the Degree Scale CMB B-mode Angular Power Spectrum with POLARBEAR
• The Origin of Parity Violation in Polarized Dust Emission and Implications for Cosmic Birefringence
• QUIJOTE scientific results -- IV. A northern sky survey in intensity and polarization at 10-20GHz with the Multi-Frequency Instrument
• The large scale polarization explorer (LSPE) for CMB measurements: performance forecast
• A Demonstration of Improved Constraints on Primordial Gravitational Waves with Delensing
• QUBIC I: Overview and ScienceProgram
• A minimal power-spectrum-based moment expansion for CMB B-mode searches
• The bispectrum of polarized galactic foregrounds
• The Simons Observatory: gain, bandpass and polarization-angle calibration requirements for B-mode searches
• Impact of Polarized Galactic Foreground Emission on CMB Lensing Reconstruction and Delensing of B-Modes
• Characterizing bias on large scale CMB $B$-modes after galactic foregrounds cleaning
• The global structure of magnetic fields and gas in simulated Milky Way-analogue galaxies
• The Simons Observatory: Galactic Science Goals and Forecasts
• Measurement of the Cosmic Microwave Background Polarization Lensing Power Spectrum from Two Years of POLARBEAR Data
• The Simons Observatory: pipeline comparison and validation for large-scale B-modes
• ForSE: a GAN based algorithm for extending CMB foreground models to sub-degree angular scales
• Evidence for the Cross-correlation between Cosmic Microwave Background Polarization Lensing from POLARBEAR and Cosmic Shear from Subaru Hyper Suprime-Cam
• Full-sky Models of Galactic Microwave Emission and Polarization at Sub-arcminute Scales for the Python Sky Model
• Tensor-to-scalar ratio forecasts for extended LiteBIRD frequency configurations
• Constraints on the spectral index of polarized synchrotron emission from WMAP and Faraday-corrected S-PASS data
• In-flight polarization angle calibration for LiteBIRD: blind challenge and cosmological implications
• Characterization of the polarized synchrotron emission from Planck and WMAP data
• Principal component analysis of the primordial tensor power spectrum
• Inpainting Galactic Foreground Intensity and Polarization maps using Convolutional Neural Network
• QUIJOTE scientific results -- VIII. Diffuse polarized foregrounds from component separation with QUIJOTE-MFI
• On the Detection of CMB B-modes from Ground at Low Frequency
• Dust polarization spectral dependence from Planck HFI data. Turning point on CMB polarization foregrounds modelling
• Foreground model recognition through Neural Networks for CMB B-mode observations
• CENN: A fully convolutional neural network for CMB recovery in realistic microwave sky simulations
• The C-Band All-Sky Survey (C-BASS): Constraining diffuse Galactic radio emission in the North Celestial Pole region
• hammurabi X: Simulating Galactic Synchrotron Emission with Random Magnetic Fields
• Polarized Synchrotron Foreground Assessment for CMB Experiments
• Optimization of foreground moment deprojection for semi-blind CMB polarization reconstruction
• A hybrid map-$C_{\ell }$ component separation method for primordial CMB $B$-mode searches
• Morphological Analysis of the Polarized Synchrotron Emission with WMAP and Planck
• Hierarchical Bayesian CMB Component Separation with the No-U-Turn Sampler
• The spectral index of polarized diffuse Galactic emission between 30 and 44 GHz
• Recovering Cosmic Microwave Background Polarization Signals with Machine Learning
• LiteBIRD Science Goals and Forecasts: Primordial Magnetic Fields
• Statistical properties of polarized CMB foreground maps
• CMB foreground measurements through broad-band radio spectro-polarimetry: prospects of the SKA-MPG telescope
• Foreground removal with ILC methods for AliCPT-1
• The Atacama Cosmology Telescope: DR6 Power Spectrum Foreground Model and Validation
• A framework to mitigate patchy reionization contamination on the primordial gravitational wave signal
• The STRIP instrument of the Large Scale Polarization Explorer: microwave eyes to map the Galactic polarized foregrounds
• CMB Shadows: The Effect of Interstellar Extinction on Cosmic Microwave Background Polarization and Temperature Anisotropy
• QUIJOTE scientific results -- VI. The Haze as seen by QUIJOTE
• Identifying frequency decorrelated dust residuals in B-mode maps by exploiting the spectral capability of bolometric interferometry
• The Simons Observatory: Assessing the Impact of Dust Complexity on the Recovery of Primordial $B$-modes
• Cosmoglobe DR1. III. First full-sky model of polarized synchrotron emission from all WMAP and Planck LFI data
• Bandpass mismatch error for satellite CMB experiments II: Correcting for the spurious signal
• Statistical properties of Galactic synchrotron temperature and polarization maps -- a multi-frequency comparison
• ForSE+: Simulating non-Gaussian CMB foregrounds at 3 arcminutes in a stochastic way based on a generative adversarial network
• Design and Performance of 30/40 GHz Diplexed Focal Plane for BICEP Array
• Delensing for Precision Cosmology: Optimizing Future CMB B-mode Surveys to Constrain r
• LiteBIRD science goals and forecasts: improved full-sky reconstruction of the gravitational lensing potential through the combination of Planck and LiteBIRD data
• Do We Have Sufficient Knowledge of the Galactic Foreground Emission in Cosmic Microwave Background Science?
• A new approach of estimating the Galactic thermal dust and synchrotron polarized emission template in the microwave bands