@article{10902/34479,
year = {2011},
month = {6},
url = {https://hdl.handle.net/10902/34479},
abstract = {We present a methodology to recover cosmic microwave background (CMB) polarization in
which the quantity P = Q + iU is linearly combined at different frequencies using complex
coefficients. This is the most general linear combination of the Q and U Stokes parameters
which preserves the physical coherence of the residual contribution on the CMB estimation.
The approach is applied to the internal linear combination (ILC) and the internal template
fitting (ITF) methodologies. The variance of P of the resulting map is minimized to compute
the coefficients of the linear combination. One of the key aspects of this procedure is that it
serves to account for a global frequency-dependent shift of the polarization phase. Although
in the standard case, in which no global E-B transference depending on frequency is expected in the foreground components, minimizing |P|² is similar to minimizing Q² and U²
separately (as previous methodologies proceed), multiplying Q and U by different coefficients
induces arbitrary changes in the polarization angle and it does not preserve the coherence
between the spinorial components. The approach is tested on simulations, obtaining a similar
residual level with respect to the one obtained with other implementations of the ILC, and
perceiving the polarization rotation of a toy model with the frequency dependence of the
Faraday rotation.},
organization = {Partial financial support from the Spanish Ministerio de Economía y Competitividad Projects AYA2010-21766-C03-01, AYA2012-39475-C02-01 and Consolider-Ingenio 2010 CSD2010-00064 is acknowledged.},
publisher = {Oxford University Press},
publisher = {Monthly Notices of the Royal Astronomical Society, 2016, 459(1), 441-454},
title = {Exploring two-spin internal linear combinations for the recovery of the CMB polarization},
author = {Fernández Cobos, Raúl and Marcos Caballero, Airam Eduardo and Vielva Martínez, Patricio and Martínez González, Enrique and Barreiro Vilas, Rita Belén},
}