Forecasts on the contamination induced by unresolved point sources in primordial non-Gaussianity beyond Planck

Abstract

In this paper we present forecasts of the contamination on different shapes of the primordial non-Gaussianity fnl parameter -- detectable on future Cosmic Microwave Background (CMB) high--resolution anisotropy maps -- produced by unresolved extragalactic point sources at frequencies of cosmological interest (45--375 GHz). We consider two scenarios: an ideal (noiseless) mission and a possible future space-borne satellite, with instrumental characteristics similar to the ones proposed for the Cosmic Origins Explorer (COrE). The local, equilateral, orthogonal and flat shapes are considered in both temperature (intensity) and polarized emission data. The angular power spectrum and bispectrum of extragalactic point sources are estimated by state-of-the-art models of source number counts. The impact of all the most relevant (far--IR and radio selected) source populations on these shapes at COrE frequencies is studied. The results of this analysis show that unresolved extragalactic point sources should not induce a very relevant non-Gaussian signal in the frequency range 100--200 GHz, thus not preventing a correct estimate of the CMB primordial fnl parameter. Polarization information allows one to significantly reduce the error--bars in the fnl parameter and the bias induced by unresolved sources and, hence, to widen the range of frequencies for fnl studies. On the contrary, at nu < 100 GHz or nu > 225 GHz, important non-Gaussian deviations in CMB anisotropy maps are expected due to unresolved extragalactic sources.

16 pages, 7 figures, 5 tables. Minor revision, accepted for publication in MNRAS

References in corpus (18)

• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• The Detection of a Population of Submillimeter-Bright, Strongly-Lensed Galaxies
• Primordial perturbations and non-Gaussianities in DBI and general multi-field inflation
• Astrophysical and Cosmological Information from Large-scale sub-mm Surveys of Extragalactic Sources
• HerMES: Cosmic Infrared Background Anisotropies and the Clustering of Dusty Star-Forming Galaxies
• Herschel-ATLAS: Multi-wavelength SEDs and physical properties of 250 micron-selected galaxies at z < 0.5
• Fast Estimator of Primordial Non-Gaussianity from Temperature and Polarization Anisotropies in the Cosmic Microwave Background
• The Atacama Cosmology Telescope: Extragalactic Sources at 148 GHz in the 2008 Survey
• Impact of Secondary non-Gaussianities on the Search for Primordial Non-Gaussianity with CMB Maps
• The extragalactic radio-source population at 95 GHz
• The impact of polarized extragalactic radio sources on the detection of CMB anisotropies in polarization
• Statistical properties of extragalactic sources in the New Extragalactic WMAP Point Source (NEWPS) catalogue
• Point Source Contamination in CMB Non-Gaussianity Analyses
• Long Gamma-Ray Bursts and Their Host Galaxies at High Redshift
• Herschel-ATLAS/GAMA: spatial clustering of low-redshift sub-mm galaxies
• Statistical analysis of undetected point sources in cosmic microwave background maps
• Large non-Gaussianity generated at the end of Extended D-term Hybrid Inflation
• Mining the Herschel-ATLAS: submillimeter-selected blazars in equatorial fields

Cited by in corpus (17)

• Planck 2013 Results. XXIV. Constraints on primordial non-Gaussianity
• Planck 2015 results. III. LFI systematic uncertainties
• Exploring Cosmic Origins with CORE: B-mode Component Separation
• Impact of polarised extragalactic sources on the measurement of CMB B-mode anisotropies
• Forecasting Polarized Radio Sources for CMB observations
• CMB B-mode non-Gaussianity: optimal bispectrum estimator and Fisher forecasts
• Average fractional polarization of extragalactic sources at Planck frequencies
• Statistics of the fractional polarisation of extragalactic dusty sources in Planck HFI maps
• General CMB bispectrum analysis using wavelets and separable modes
• Constraining the WMAP9 bispectrum and trispectrum with needlets
• The CIB-lensing bispectrum: impact on primordial non-Gaussianity and detectability for the Planck mission
• Joint Bayesian estimation of tensor and lensing B-modes in the power spectrum of CMB polarization data
• The Q/U Imaging Experiment: Polarization Measurements of Radio Sources at 43 and 95 GHz
• Optimal estimator for the amplitude of the bispectrum from IR sources
• The C-Band All-Sky Survey (C-BASS): Total intensity point-source detection over the northern sky
• Mitigating point-source contamination in CMB polarization: a Generalized Point Spread Function fitting approach
• On the detection of point sources in Planck LFI 70 GHz CMB maps based on cleaned K-map