Calabrese, Erminia ![]() |
Preview |
PDF
- Published Version
Download (1MB) | Preview |
Abstract
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 SachsWolfe 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 foregroundcleaned maps using the KQ75 mask out to lmax ¼ 600. We find no significant evidence for a nonzero nonGaussian 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 nonGaussianity. 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 þ W maps is fNL ¼ 13 � 62, when marginalized over point sources and lensing-ISW/SZ contributions to the total bispectrum.
Item Type: | Article |
---|---|
Date Type: | Publication |
Status: | Published |
Schools: | Physics and Astronomy |
Subjects: | Q Science > QB Astronomy |
Publisher: | American Physical Society |
ISSN: | 1550-7998 |
Date of First Compliant Deposit: | 10 October 2017 |
Date of Acceptance: | 25 September 2009 |
Last Modified: | 05 May 2023 23:33 |
URI: | https://orca.cardiff.ac.uk/id/eprint/105356 |
Citation Data
Cited 16 times in Scopus. View in Scopus. Powered By Scopus® Data
Actions (repository staff only)
![]() |
Edit Item |