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Cosmic Microwave Background Polarization and Temperature Power Spectra Estimation Using Linear Combination of WMAP 5 Year Maps

Samal, Pramoda Kumar and Saha, Rajib and Delabrouille, Jacques and Prunet, Simon and Jain, Pankaj and Souradeep, Tarun (2010) Cosmic Microwave Background Polarization and Temperature Power Spectra Estimation Using Linear Combination of WMAP 5 Year Maps. Astrophysical Journal, 714 (1). pp. 840-851. ISSN 0004-637X.

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We estimate cosmic microwave background (CMB) polarization and temperature power spectra using Wilkinson Microwave Anisotropy Probe (WMAP) 5 year foreground contaminated maps. The power spectrum is estimated by using a model-independent method, which does not utilize directly the diffuse foreground templates nor the detector noise model. The method essentially consists of two steps: (1) removal of diffuse foregrounds contamination by making linear combination of individual maps in harmonic space and (2) cross-correlation of foreground cleaned maps to minimize detector noise bias. For the temperature power spectrum we also estimate and subtract residual unresolved point source contamination in the cross-power spectrum using the point source model provided by the WMAP science team. Our TT, TE, and EE power spectra are in good agreement with the published results of the WMAP science team. We perform detailed numerical simulations to test for bias in our procedure. We find that the bias is small in almost all cases. A negative bias at low l in TT power spectrum has been pointed out in an earlier publication. We find that the bias-corrected quadrupole power (l(l + 1)C_(l)/2π) is 532 μK^2, approximately 2.5 times the estimate (213.4 μK^2) made by the WMAP team.

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Additional Information:© 2010 American Astronomical Society. Received 2009 March 26; accepted 2010 March 2; published 2010 April 15. We acknowledge the use of the Legacy Archive for Microwave Background Data Analysis. Some of the results of this work are derived using the publicly available HEALPIx package (G´orski et al. 2005). (The HEALPIX distribution is publicly available from the Web site We acknowledge the use of the PSM, developed by the Component Separation Working Group (WG2) of the Planck Collaboration. Pramoda K. Samal acknowledges CSIR, India for financial support under the research grant CSIR-SRF- 9/92(340)/2004- EMR-I. A portion of the research described in this paper was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.
Funding AgencyGrant Number
Council of Scientific and Industrial Research (CSIR), IndiaCSIR-SRF- 9/92(340)/2004-EMR-I
Subject Keywords:cosmic background radiation; methods: data analysis; polarization
Issue or Number:1
Classification Code:PACS: 98.70.Vc; 95.30.Tg
Record Number:CaltechAUTHORS:20100604-110521927
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Official Citation:Pramoda Kumar Samal et al 2010 ApJ 714 840 doi: 10.1088/0004-637X/714/1/840
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:18562
Deposited By: Jason Perez
Deposited On:04 Jun 2010 21:30
Last Modified:03 Oct 2019 01:44

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