Planck 2013 results. XII. Diffuse component separation
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Planck has produced detailed all-sky observations over nine frequency bands between 30 and 857 GHz. These observations allow robust reconstruction of the primordial cosmic microwave background (CMB) temperature fluctuations over nearly the full sky, as well as new constraints on Galactic foregrounds, including thermal dust and line emission from molecular carbon monoxide (CO). This paper describes the component separation framework adopted by Planck for many cosmological analyses, including CMB power spectrum determination and likelihood construction on large angular scales, studies of primordial non-Gaussianity and statistical isotropy, the integrated Sachs-Wolfe effect, gravitational lensing, and searches for topological defects. We test four foreground-cleaned CMB maps derived using qualitatively different component separation algorithms. The quality of our reconstructions is evaluated through detailed simulations and internal comparisons, and shown through various tests to be internally consistent and robust for CMB power spectrum and cosmological parameter estimation up to ℓ = 2000. The parameter constraints on ΛCDM cosmologies derived from these maps are consistent with those presented in the cross-spectrum based Planck likelihood analysis. We choose two of the CMB maps for specific scientific goals. We also present maps and frequency spectra of the Galactic low-frequency, CO, and thermal dust emission. The component maps are found to provide a faithful representation of the sky, as evaluated by simulations, with the largest bias seen in the CO component at 3%. For the low-frequency component, the spectral index varies widely over the sky, ranging from about β = −4 to − 2. Considering both morphology and prior knowledge of the low frequencycomponents, the index map allows us to associate a steep spectral index (β< −3.2) with strong anomalous microwave emission, corresponding to a spinning dust spectrum peaking below 20 GHz, a flat index of β> −2.3 with strong free-free emission, and intermediate values with synchrotron emission.
Date Issued
2014-11-01
Date Acceptance
2013-12-18
Citation
Astronomy and Astrophysics, 2014, 571
ISSN
0004-6361
Publisher
EDP Sciences
Journal / Book Title
Astronomy and Astrophysics
Volume
571
Copyright Statement
© ESO, 2014. Reproduced with permission from Astronomy & Astrophysics, © ESO.
Sponsor
Science and Technology Facilities Council (STFC)
Science and Technology Facilities Council (STFC)
Science and Technology Facilities Council (STFC)
Science and Technology Facilities Council (STFC)
Science and Technology Facilities Council (STFC)
Science and Technology Facilities Council (STFC)
Science and Technology Facilities Council (STFC)
Science and Technology Facilities Council (STFC)
Science and Technology Facilities Council [2006-2012]
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000345282600026&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Grant Number
ST/H001239/1
ST/G003874/1
ST/I005765/1
ST/J004812/1
ST/J001368/1
ST/K001051/1
ST/L001314/1
ST/K004131/1
ST/K001051/1
Subjects
Science & Technology
Physical Sciences
Astronomy & Astrophysics
cosmic background radiation
MICROWAVE-ANISOTROPY-PROBE
INTERSTELLAR-MEDIUM EMISSION
TEMPERATURE POWER SPECTRUM
SPINNING DUST
FOREGROUND EMISSION
FULL-SKY
GALACTIC EMISSION
WMAP OBSERVATIONS
POLARIZATION DATA
LIKELIHOOD
Publication Status
Published
Article Number
ARTN A12
Date Publish Online
2014-10-29