J/A+A/578/A44 Map of foreground masks for Planck (Axelsson+, 2015)
Testing for foreground residuals in the Planck foreground cleaned maps:
A new method for designing confidence masks.
Axelsson M., Ihle H.T., Scodeller S., Hansen F.K.
<Astron. Astrophys. 578, A44 (2015)>
=2015A&A...578A..44A 2015A&A...578A..44A
ADC_Keywords: Positional data
Keywords: cosmic background radiation - cosmology: observations -
methods: numerical
Abstract:
We test for foreground residuals in the foreground cleaned Planck
Cosmic Microwave Background (CMB) maps outside and inside U73 mask
commonly used for cosmological analysis. The aim of this paper is to
introduce a new method to validate masks by looking at the differences
in cleaned maps obtained by different component separation methods. By
analyzing the power spectrum as well as the mean, variance and
skewness of needlet coefficients on bands outside and inside the U73
mask we first confirm that the pixels already masked by U73 are highly
contaminated and cannot be used for cosmological analysis. We further
find that the U73 mask needs extension in order to reduce large scale
foreground residuals to a level of less than 20% of the standard
deviation of CMB fluctuations within the bands closest to the galactic
equator. We also find 276 point sources in the cleaned foreground maps
which are currently not masked by the U73 mask. Our final publicly
available extended mask leaves 65.9% of the sky for cosmological
analysis. Note that this extended mask may be important for analyses
on local sky patches; in full sky analyses the additional residuals
near the galactic equator may average out.
Description:
FITs file contains an nside=2048 healpix map of our confidence mask
that masks 65.9% of the sky. The pixel convention used is: ring order.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 60 1 Informations of FITS file
mask.fits 2880 69908 FITS file (Healpix mask)
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- Nmasks [49152] Number of masks
7- 12 I6 Kibyte size [196616] Size of the FITS file
14- 38 A25 --- FileName Name of the FITS file
40- 60 A21 --- Title Title of the file
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Acknowledgements:
Magnus Axelsson, magnus.axelsson(at)astro.uio.no
(End) Patricia Vannier [CDS] 24-Mar-2015