Polarized galactic synchrotron and dust emission and their correlation

Journal Article · Tue Dec 01 04:00:00 EST 2015 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2015/12/020· OSTI ID:22525137

Choi, Steve K.

We present an analysis of the level of polarized dust and synchrotron emission using the WMAP9 and Planck data. The primary goal of this study is to inform the assessment of foreground contamination in the cosmic microwave background (CMB) measurements below ℓ ∼ 200 from 23 to 353 GHz. We compute angular power spectra as a function of sky cut based on the Planck 353 GHz polarization maps. Our primary findings are the following. (1) There is a spatial correlation between the dust emission as measured by Planck at 353 GHz and the synchrotron emission as measured by WMAP at 23 GHz with ρ ≈ 0.4 or greater for ℓ < 20 and f{sub sky} ≥ 0.5, dropping to ρ ≈ 0.2 for 30 < ℓ < 200. (2) A simple foreground model with dust, synchrotron, and their correlation fits well to all possible cross spectra formed with the WMAP and Planck 353 GHz data given the current uncertainties. (3) In the 50% cleanest region of the polarized dust map, the ratio of synchrotron to dust amplitudes at 90 GHz for 50 ≤ ℓ ≤110 is 0.3{sub −0.2}{sup +0.3}. Smaller regions of sky can be cleaner although the uncertainties in our knowledge of synchrotron emission are larger. A high-sensitivity measurement of synchrotron below 90 GHz will be important for understanding all the components of foreground emission near 90 GHz.

• OSTI ID: 22525137
• Journal Information: Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 12 Vol. 2015; ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
AMPLITUDES
CORRELATIONS
COSMIC DUST
ENERGY SPECTRA
GALAXIES
GHZ RANGE
POLARIZATION
RELICT RADIATION
SENSITIVITY
SYNCHROTRON RADIATION