Non-Gaussianity in WMAP data due to the correlation of CMB lensing potential with secondary anisotropies

Journal Article · Sun Feb 14 23:00:00 EST 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.81.043529· OSTI ID:21409282

Calabrese, Erminia ^[1]; Smidt, Joseph; Amblard, Alexandre; Cooray, Asantha; Serra, Paolo ^[2]; Melchiorri, Alessandro ^[1]; Heavens, Alan ^[3]; Munshi, Dipak ^[3]

---

1. Center for Cosmology, Department of Physics and Astronomy, University of California Irvine, Irvine, California 92697 (United States)
2. Physics Department and INFN, Universita' di Roma 'La Sapienza', Ple Aldo Moro 2, 00185, Rome (Italy)
3. Scottish Universities Physics Alliance (SUPA), Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom)

We measure the skewness power spectrum of the CMB anisotropies optimized for a detection of the secondary bispectrum generated by the correlation of the CMB lensing potential with integrated Sachs-Wolfe effect and the Sunyaev-Zel'dovich effect. The covariance of our measurements is generated by Monte Carlo simulations of Gaussian CMB fields with noise properties consistent with WMAP 5-year data. When interpreting multifrequency measurements we also take into account the confusion resulting from unresolved radio point sources. We analyze Q, V and W-band WMAP 5-year raw and foreground-cleaned maps using the KQ75 mask out to l{sub max}=600. We find no significant evidence for a nonzero non-Gaussian signal from the lensing-secondary correlation in all three bands and we constrain the overall amplitude of the cross-power spectrum between CMB lensing potential and the sum of SZ and ISW fluctuations to be 0.42{+-}0.86 and 1.19{+-}0.86 in combined V and W-band raw and foreground-cleaned maps provided by the WMAP team, respectively. The point-source amplitude at the bispectrum level measured with this skewness power spectrum is higher than previous measurements of point-source non-Gaussianity. We also consider an analysis where we also account for the primordial non-Gaussianity in addition to lensing-secondary bispectrum and point sources. The focus of this paper is on secondary anisotropies. Consequently the estimator is not optimized for primordial non-Gaussianity and the limit we find on local non-Gaussianity from the foreground-cleaned V+W maps is f{sub NL}=-13{+-}62, when marginalized over point sources and lensing-ISW/SZ contributions to the total bispectrum.

• OSTI ID: 21409282
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 4 Vol. 81; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
AMPLITUDES
ANISOTROPY
ASYMMETRY
CALCULATION METHODS
COMPUTERIZED SIMULATION
CORRELATIONS
DETECTION
DISTRIBUTION
ELECTROMAGNETIC RADIATION
FLUCTUATIONS
MICROWAVE RADIATION
MONTE CARLO METHOD
NOISE
POINT SOURCES
RADIATION SOURCES
RADIATIONS
RELICT RADIATION
SIMULATION
SPECTRA
VARIATIONS