Point Source Contamination in CMB Non-Gaussianity Analyses

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dc.creatorBabich, Daniel
dc.creatorPierpaoli, Elena
dc.date2008-03-07
dc.date2008-03-27
dc.date.accessioned2026-07-07T11:40:42Z
dc.date.available2026-07-07T11:40:42Z
dc.descriptionIn this paper we analyze the biasing effect of point sources, either thermal Sunyaev-Zeldovich clusters or standard radio sources, on the estimated strength of the non-Gaussianity in the Cosmic Microwave Background (CMB). We show that the biggest contribution comes from the cross--correlation of the CMB with the matter density rather than from the poisson term which is conventionally assumed in these calculations. For the three year WMAP data, we estimate that point sources could produce a non--Gaussian signature equivalent to a bias in $f_{NL}$ of $0.35, 0.24, -0.097, -0.13$ in the Ka, Q, V and W bands respectively. The level of bias we find is largely insufficient to explain the very high $f_{NL}$ values recently detected by Yadav and Wandelt. For Planck, we estimate the point source bispectra to contaminate the $f_{NL}$ estimator with a bias of $1.3, 0.34, -0.25, -0.48$ at $30, 44, 70, 100 {\rm GHz}$ respectively. These results depend on the assumed redshift distribution of the point sources. However, given the projected Planck sensitivity of $Δf_{NL} \simeq 5$ (95 % C.L.), a good estimate of point sources' properties including their number density and redshift distribution is essential before deriving strong conclusions on primordial non--Gaussianity.
dc.description15 pages, 7 figures. To be submitted to PRD
dc.identifierhttps://arxiv.org/abs/0803.1161
dc.identifierhttp://arxiv.org/abs/0803.1161
dc.identifierPhys.Rev.D77:123011,2008
dc.identifierdoi:10.1103/PhysRevD.77.123011
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/200334
dc.subjectAstrophysics
dc.titlePoint Source Contamination in CMB Non-Gaussianity Analyses
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