Cosmic Microwave Background Polarisation: foreground contrast and component separation

Abstract

We evaluate the expected level of foreground contamination to the cosmic microwave background (CMB) polarised radiation, focusing on the diffuse emission from our own Galaxy. In particular, we perform a first attempt to simulate an all sky template of polarised emission from thermal dust. This study indicates that the foreground contamination to CMB $B$ modes is likely to be relevant on all frequencies, and even at high Galactic latitudes. We review the recent developments in the design of data analysis techniques dedicated to the separation of CMB and foreground emissions in multi-frequency observations, exploiting their statistical independence. We argue that the high quality and detail of the present CMB observations represent an almost ideal statistical dataset where these algorithms can operate with excellent performance. We explicitly show that the recovery of CMB $B$ modes is possible even if they are well below the foreground level, working at the arcmin. resolution at an almost null computational cost. This capability well represents the great potentiality of these new data analysis techniques, which should be seriously taken into account for implementation in present and future CMB observations.

10 pages, 4 figures, to be published in the proceedings of ``The Cosmic Microwave Background and its Polarization", New Astronomy Reviews, (eds. S. Hanany and K.A. Olive). Maps and software downloads at http://planck.mpa-garching.mpg.de/ and http://www.sissa.it/~bacci/cmb/downloads/

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Cited by in corpus (13)

• Planck intermediate results. XXX. The angular power spectrum of polarized dust emission at intermediate and high Galactic latitudes
• Characterization of foreground emission at degree angular scale for CMB B-modes observations. Thermal Dust and Synchrotron signal from Planck and WMAP data
• Scientific optimization of a ground-based CMB polarization experiment
• Making Maps from Planck LFI 30GHz Data
• ForSE: a GAN based algorithm for extending CMB foreground models to sub-degree angular scales
• MillimeterDL: Deep Learning Simulations of the Microwave Sky
• A 3D model for CO molecular line emission as a potential CMB polarization contaminant
• Separating polarized cosmological and galactic emissions for CMB B-mode polarization experiments
• Blind component separation for polarized observations of the CMB
• CENN: A fully convolutional neural network for CMB recovery in realistic microwave sky simulations
• STARS: A software application for the EBEX autonomous daytime star cameras
• Software systems for operation, control, and monitoring of the EBEX instrument
• Dipolar radiation from spinning dust grains coupled to an electromagnetic wave