Statistical properties of Galactic synchrotron temperature and polarization maps -- a multi-frequency comparison

Abstract

Understanding the statistical properties of synchrotron emission from our Galaxy is valuable from the perspective of observations targeting signals of cosmological origin, as well as for understanding physical processes in our Galaxy. In this work, we extend the analysis of arXiv:2104.00419v2 to -- (a) all-sky observed maps of total foreground emissions at different frequencies provided by WMAP, Planck and Stockert-Villa, (b) component separated synchrotron temperature maps provided by WMAP, Planck and BeyondPlanck, and (c) component separated polarization maps provided by WMAP and Planck. The tools we use are Minkowski functionals and tensors. Our main goals are twofold. First, we determine the variation of morphological properties of the total foreground maps with observing frequency and compare with simulations. This elucidates how the morphology varies due to the relative dominance of different foreground components at different frequencies. Next, we analyze the nature of non-Gaussianity and statistical isotropy of synchrotron fluctuations on smaller scales using various component separated synchrotron temperature and polarization maps. We find that all maps exhibit kurtosis non-Gaussianity, in agreement with the Haslam map. This result can be an important input for the modelling of small-scale synchrotron fluctuations for component separation pipelines. This also suggests that residual synchrotron contamination in CMB will manifest as kurtosis. Studying different component separated maps, we find that BeyondPlanck and WMAP MCMC-e agree well with Haslam at all scales. The other maps show differences of varying statistical significance. Our analysis suggests a combination of residual AME and/or free-free emissions and point sources as contributing to these differences, and underscores the need for further improvement of the pipelines.

arXiv commentPublished in JCAP, 33 pages, 16 figures

References in corpus (54)

• HEALPix -- a Framework for High Resolution Discretization, and Fast Analysis of Data Distributed on the Sphere
• Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Parameter Results
• Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Final Maps and Results
• Planck 2018 results. I. Overview and the cosmological legacy of Planck
• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Foreground Emission
• Planck 2018 results. IV. Diffuse component separation
• A unified pseudo-$C_{\ell }$ framework
• Planck 2018 results. III. High Frequency Instrument data processing and frequency maps
• Foregrounds and Forecasts for the Cosmic Microwave Background
• Joint Bayesian component separation and CMB power spectrum estimation
• A full sky, low foreground, high resolution CMB map from WMAP
• Foreground simulations for the LOFAR - Epoch of Reionization Experiment
• The Python Sky Model: software for simulating the Galactic microwave sky
• Minkowski Functionals used in the Morphological Analysis of Cosmic Microwave Background Anisotropy Maps
• Separation of anomalous and synchrotron emissions using WMAP polarization data
• Power spectrum estimation from high-resolution maps by Gibbs sampling
• Planck 2018 results. XI. Polarized dust foregrounds
• The interstellar cosmic-ray electron spectrum from synchrotron radiation and direct measurements
• Galactic synchrotron emission with cosmic ray propagation models
• A determination of the Spectra of Galactic components observed by WMAP
• Simulating polarized Galactic synchrotron emission at all frequencies, the Hammurabi code
• Statistical Description of Synchrotron Intensity Fluctuations: Studies of Astrophysical Magnetic Turbulence
• The S-PASS view of polarized Galactic Synchrotron at 2.3 GHz as a contaminant to CMB observations
• Analytic Minkowski Functionals of the Cosmic Microwave Background: Second-order Non-Gaussianity with Bispectrum and Trispectrum
• Non-Gaussian statistics of critical sets in 2 and 3D: Peaks, voids, saddles, genus and skeleton
• Polarised radio filaments outside the Galactic plane
• S-band Polarization All Sky Survey (S-PASS): survey description and maps
• Synchrotron Spectral Curvature from 22 MHz to 23 GHz
• QUIJOTE scientific results -- IV. A northern sky survey in intensity and polarization at 10-20GHz with the Multi-Frequency Instrument
• Power spectrum of the polarized diffuse Galactic radio emission
• The impact of Galactic synchrotron emission on CMB anisotropy measurements. I. Angular power spectrum analysis of total intensity all-sky surveys
• Loops and spurs: The angular power spectrum of the Galactic synchrotron background
• The bispectrum of polarized galactic foregrounds
• A radio continuum survey of the southern sky at 1420 MHz. Observations and data reduction
• Galactic foregrounds: Spatial fluctuations and a procedure of removal
• Foreground Analysis Using Cross-Correlations of External Templates on the 7-year WMAP data
• Statistical properties of galactic CMB foregrounds: dust and synchrotron
• On Minkowski Functionals of CMB polarization
• BeyondPlanck XIII. Intensity foreground sampling, degeneracies, and priors
• Weakly non-Gaussian formula for the Minkowski functionals in general dimensions
• Constraints on the spectral index of polarized synchrotron emission from WMAP and Faraday-corrected S-PASS data
• Characterization of the polarized synchrotron emission from Planck and WMAP data
• The bispectra of galactic CMB foregrounds and their impact on primordial non-Gaussianity estimation
• Residual foreground contamination in the WMAP data and bias in non-Gaussianity estimation
• The C-Band All-Sky Survey (C-BASS): Template Fitting of Diffuse Galactic Microwave Emission in the Northern Sky
• Cosmoglobe DR1 results. I. Improved Wilkinson Microwave Anisotropy Probe maps through Bayesian end-to-end analysis
• Skewness and Kurtosis as Indicators of Non-Gaussianity in Galactic Foreground Maps
• The nature of non-Gaussianity and statistical isotropy of the 408 MHz Haslam synchrotron map
• Morphological Analysis of the Polarized Synchrotron Emission with WMAP and Planck
• Simulated foreground predictions for HI at z = 3.35 with the Ooty Wide Field Array: I. Instrument and the foregrounds
• The spectral index of polarized diffuse Galactic emission between 30 and 44 GHz
• Non-Gaussianity of diffuse Galactic synchrotron emission at 408 MHz
• Statistical properties of polarized CMB foreground maps
• The geometrical meaning of statistical isotropy of smooth random fields in two dimensions