Implications of scattering for CMB foreground emission modelling

Abstract

Context. The extreme precision and accuracy of forthcoming observations of CMB temperature and polarization anisotropies, aiming to detect the tiny signatures of primordial gravitational waves or of light relic particles beyond the standard three light neutrinos, requires commensurate precision in the modelling of foreground Galactic emission that contaminates CMB observations. Aims. We evaluate the impact of second-order effects in Galactic foreground emission due to Thomson scattering off interstellar free electrons and to Rayleigh scattering off interstellar dust particles. Methods. We use existing sky survey data and models of the distribution of free electrons and dust within the Milky Way to estimate the amplitude and power spectra of the emission originating from radiation scattered either by free electrons or by dust grains at CMB frequencies. Results. Both processes generate corrections to the total emission that are small compared to direct emission, and are small enough not to pose problems for current-generation observations. Conclusions. However, B-modes generated by Thomson scattering of incoming radiation by interstellar free electrons at CMB frequencies are within an order of magnitude of the sensitivity of the most advanced forthcoming CMB telescopes, and might require more precise evaluation in the future.

8 pages, 5 figures

References in corpus (44)

• The ATNF Pulsar Catalogue
• Dust Grain Size Distributions and Extinction in the Milky Way, LMC, and SMC
• Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Final Maps and Results
• Planck 2018 results. I. Overview and the cosmological legacy of Planck
• BICEP2 I: Detection Of B-mode Polarization at Degree Angular Scales
• The Simons Observatory: Science goals and forecasts
• A New Electron Density Model for Estimation of Pulsar and FRB Distances
• The Interstellar Environment of our Galaxy
• The 10 Meter South Pole Telescope
• A Full-Sky H-alpha Template for Microwave Foreground Prediction
• A CMB Polarization Primer
• Planck 2018 results. IV. Diffuse component separation
• Tracing Magnetic Fields with Aligned Grains
• Radio observational constraints on Galactic 3D-emission models
• Joint Bayesian component separation and CMB power spectrum estimation
• A full sky, low foreground, high resolution CMB map from WMAP
• On Foreground Removal from the Wilkinson Microwave Anisotropy Probe Data by an Internal Linear Combination Method: Limitations and Implications
• CMB-S4: Forecasting Constraints on Primordial Gravitational Waves
• Component separation methods for the Planck mission
• Extending Big Power Law in the Sky with Turbulence Spectra from WHAM data
• The pre-launch Planck Sky Model: a model of sky emission at submillimetre to centimetre wavelengths
• Towards a free-free template for CMB foregrounds
• PRISM (Polarized Radiation Imaging and Spectroscopy Mission): An Extended White Paper
• Multi-Detector Multi-Component spectral matching and applications for CMB data analysis
• CMB and SZ effect separation with Constrained Internal Linear Combinations
• The Atacama Cosmology Telescope: CMB Polarization at $200<\ell <9000$
• Exploring Cosmic Origins with CORE: Survey requirements and mission design
• Limits on the detectability of the CMB B-mode polarization imposed by foregrounds
• Exploring Cosmic Origins with CORE: B-mode Component Separation
• Peeling off foregrounds with the constrained moment ILC method to unveil primordial CMB $B$-modes
• Dispersion measure variations in a sample of 168 pulsars
• Measuring the tensor to scalar ratio from CMB B-modes in presence of foregrounds
• Forecasting performance of CMB experiments in the presence of complex foreground contaminations
• Galactic foreground contributions to the WMAP5 maps
• The CLASS 150/220 GHz Polarimeter Array: Design, Assembly, and Characterization
• BeyondPlanck III. Commander3
• RMTable2023 and PolSpectra2023: standards for reporting polarization and Faraday rotation measurements of radio sources
• $B$-mode forecast of CMB-Bh$\overline{a}$rat
• Foreground Separation and Constraints on Primordial Gravitational Waves with the PICO Space Mission
• Disentangling the Faraday rotation sky
• Grey Milky Way Extinction from SDSS Stellar Photometry
• On the quasistatic optimal plasmonic resonances in lossy media
• Forecast of foreground cleaning strategies for AliCPT-1
• CMB Shadows: The Effect of Interstellar Extinction on Cosmic Microwave Background Polarization and Temperature Anisotropy

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