Work

Statistical properties of Galactic CMB foregrounds: dust and synchrotron

Year: 2018

Type: article

Abstract: Recent Planck observations have revealed some of the important statistical properties of synchrotron and dust polarization, namely, the B to E mode power and temperature–E (TE) mode cross-correlation. In this paper, we extend our analysis in Kandel et al. that studied the B to E mode power ratio for polarized dust emission to include TE cross-correlation and develop an analogous formalism for synchrotron signal, all using a realistic model of magnetohydrodynamical turbulence. Our results suggest that the Planck results for both synchrotron and dust polarization can be understood if the turbulence in the Galaxy is sufficiently sub-Alfvénic. Making use of the observed poor magnetic field–density correlation, we show that the observed positive TE correlation for dust corresponds to our theoretical expectations. We also show how the B to E ratio as well as the TE cross-correlation can be used to study media magnetization, compressibility, and level of density–magnetic field correlation.

Source: Monthly Notices of the Royal Astronomical Society

DOI: 10.1093/mnras/sty1115

Authors: D Kandel, A Lazarian, D Pogosyan

Institutions: University of Alberta, Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, University of Wisconsin–Madison

Language: English

Topic: Cosmology and Gravitation Theories

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green

Funder: National Science Foundation

Awards: Collaborative Research: A Higher Order PDE Toolkit for Computational Mathematics and Astrophysical Turbulence, Collaborative Research: Using Observations and Models to Study How Dust Grains Between the Stars Align