The effect of cosmic variance on the characteristics of dust polarization power spectra

Abstract

In the context of cosmic microwave background polarization studies and the characterization of the Galactic foregrounds, the power spectrum analysis of the thermal dust polarization sky has led to intriguing evidence of an E/B asymmetry and a positive TE correlation. In this work, we produce synthesized dust polarization maps from a set of global magneto-hydrodynamic (MHD) simulations of Milky-Way-sized galaxies, and analyze their power spectra at intermediate angular scales (angular multipoles $\ell \in \left[60,140\right]$). We study the role of the initial configuration of the large-scale magnetic field, its strength, and the feedback on the power spectrum characteristics. Using full-galaxy MHD simulations, we were able to estimate the variance induced by the peculiar location of the observer in the galaxy. We find that the polarization power spectra sensitively depend on the observer's location, impeding a distinction between different simulation setups. There is a clear statistical difference between the power spectra measured from within the spiral arms and those measured from the inter-arm regions. Also, power spectra from within supernova-driven bubbles share common characteristics, regardless of the underlying model. However, no correlation was found between the properties of the polarization power spectra and the local (with respect to the observer) mean values of physical quantities such as the density and the strength of the magnetic field. Finally, we find indications that the global strength of the magnetic field may play a role in shaping the power spectrum characteristics; as the global magnetic field strength increases, the E/B asymmetry and the TE correlation increase, whereas the viewpoint-induced variance decreases. However, we find no direct correlation with the strength of the local magnetic field that permeates the mapped region of the interstellar medium.

arXiv comment20 pages including 3 appendices. Accepted version at A&A

References in corpus (42)

• The Structure of Cold Dark Matter Halos
• HEALPix -- a Framework for High Resolution Discretization, and Fast Analysis of Data Distributed on the Sphere
• Cosmological Hydrodynamics with Adaptive Mesh Refinement: a new high resolution code called RAMSES
• Planck 2018 results. I. Overview and the cosmological legacy of Planck
• An All-Sky Analysis of Polarization in the Microwave Background
• Statistics of Cosmic Microwave Background Polarization
• A Probe of Primordial Gravity Waves and Vorticity
• Planck 2013 results. XI. All-sky model of thermal dust emission
• Trigonometric Parallaxes Of High-Mass Star Forming Regions: Our View Of The Milky Way
• Extrapolation of Galactic Dust Emission at 100 Microns to CMBR Frequencies Using FIRAS
• A High Order Godunov Scheme with Constrained Transport and Adaptive Mesh Refinement for Astrophysical MHD
• CMB Anisotropies: Total Angular Momentum Method
• Three-phase Interstellar medium in Galaxies Resolving Evolution with Star formation and Supernova feedback (TIGRESS): Algorithms, Fiducial model, and Convergence
• Magnetically Aligned HI Fibers and the Rolling Hough Transform
• Planck intermediate results. XXX. The angular power spectrum of polarized dust emission at intermediate and high Galactic latitudes
• 3D maps of interstellar dust in the Local Arm: using $Gaia$, 2MASS and APOGEE-DR14
• Planck 2018 results. XI. Polarized dust foregrounds
• Planck intermediate results. XX. Comparison of polarized thermal emission from Galactic dust with simulations of MHD turbulence
• Xspect, estimation of the angular power spectrum by computing cross-power spectra with analytical error bars
• An Intercomparison Between Divergence-Cleaning and Staggered Mesh Formulations for Numerical Magnetohydrodynamics
• Evolution of the mass, size, and star formation rate in high-redshift merging galaxies MIRAGE - A new sample of simulations with detailed stellar feedback
• Modeling the magnetized Local Bubble from dust data
• The nature of the E-B decomposition of CMB polarization
• The structure and statistics of interstellar turbulence
• The Origin of Parity Violation in Polarized Dust Emission and Implications for Cosmic Birefringence
• The Local Bubble: a magnetic veil to our Galaxy
• Evidence for Line-of-Sight Frequency Decorrelation of Polarized Dust Emission in $Planck$ Data
• Analytical models of X-shape magnetic fields in galactic halos
• SILCC-Zoom: Polarisation and depolarisation in molecular clouds
• Dust-polarization maps for local interstellar turbulence
• Dust polarization and ISM turbulence
• Dust Polarization Maps from TIGRESS: E/B power asymmetry and TE correlation
• Radiative transfer with POLARIS. II.: Modeling of synthetic Galactic synchrotron observations
• Local Bubble contribution to the 353-GHz dust polarized emission
• Can the observed E/B ratio for dust galactic foreground be explained by sub-Alfvenic turbulence?
• A systematic study of radiative torque grain alignment in the diffuse interstellar medium
• Is there a left-handed magnetic field in the solar neighborhood? Exploring helical magnetic fields in the interstellar medium through dust polarization power spectra
• E and B polarizations from inhomogeneous and solar surface turbulence
• Polarised emission from aligned dust grains in nearby galaxies: predictions from the Auriga simulations
• hammurabi X: Simulating Galactic Synchrotron Emission with Random Magnetic Fields
• The link between E-B polarization modes and gas column density from interstellar dust emission
• Magnetic fields in massive spirals: The role of feedback and initial conditions

Cited by in corpus (4)

• The Simons Observatory: Galactic Science Goals and Forecasts
• Starlight-polarization-based tomography of the magnetized interstellar medium: PASIPHAE's line-of-sight inversion method
• Non-Gaussian modelling and statistical denoising of Planck dust polarization full-sky maps using scattering transforms
• Polarization power spectra and dust cloud morphology