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Please use this identifier to cite or link to this item: http://hdl.handle.net/2289/4897

Title: Multifrequency Wiener filtering of cosmic microwave background data with polarization
Authors: Bouchet, F.R.
Prunet, S.
Sethi, S.K.
Issue Date: Feb-1999
Publisher: Blackwell Publishing for the Royal Astronomical Society
Citation: Monthly Notices of the Royal Astronomical Society, 1999, Vol.302, p663
Abstract: One goal of cosmic microwave background (CMB) data analysis is to combine data at different frequencies, angular resolutions, and noise levels in order best to extract the component with a Planckian spectral behaviour. A multifrequency Wiener filtering method has been proposed in this context by Bouchet, Gispert & Puget and in parallel by Tegmark & Efstathiou. As shown by Bouchet & Gispert, this linear method is also convenient with which to estimate a priori, given a sky model and an experimental description, the residual errors on the CMB power spectrum assuming the foregrounds have been removed with this method. In this paper, we extend the method to the case in which additional polarization data are available. In particular, we derive the errors on the power spectra involving polarization and show numerical results for the specifications of the future CMB space missions MAP and Planck1 when it is assumed that the Galactic synchrotron and dust emission are respectively about 40 and 10 per cent polarized. We consider two underlying models for our study: we take a standard CDM model with τ = 0.1 for the extraction of E-mode polarization and ET cross-correlation; for B-mode polarization we consider a tilted CDM model with ns = 0.9, nt = -0.1 and T/S = 0.7. We find the following results. (1) The resulting fractional errors on E-mode polarization and TE cross-correlation power spectra are <= 10 - 30 per cent for 50 <= l <= 1000 for Planck. The fractional errors are between 50 and 150 per cent for l <= 50. (2) The corresponding fractional errors for MAP are >= 300 per cent for most of the l range. (3) The Wiener filtering gives extraction errors of <= twice the expected performance for the combined sensitivity of all the channels of Planck. For MAP, the corresponding degradation is ~ 4. (4) If, instead of individual modes, one considers band-power estimates with a logarithmic interval Δ l /l = 0.2 then the fractional error for MAP drops to <= 100 per cent at the Doppler peak around l ~ 300 for the ET signal. (5) The fractional error for B-mode polarization detection is <= 100 per cent with Planck for l <= 100. A band-power estimate with Δ l /l = 0.2 reduces the fractional errors to <= 25 per cent for 20 <= l <= 100.
Description: Restricted Access
URI: http://hdl.handle.net/2289/4897
ISSN: 0035-8711
Alternative Location: http://adsabs.harvard.edu/abs/1999MNRAS.302..663B
http://arxiv.org/abs/10.1046/j.1365-8711.1999.02118.x
Copyright: 1999 Blackwell Publishing for the Royal Astronomical Society
Appears in Collections:Research Papers (A&A)

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