Predictions of the Angular Power Spectrum of Clustered Extragalactic Point Sources at Cosmic Microwave Background Frequencies from Flat and All‐Sky Two‐dimensional Simulations

González‐Nuevo, J.; Toffolatti, L.; Argüeso, F.

doi:10.1086/427425

Cited by 70 publications

(78 citation statements)

References 64 publications

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“…The former are radio and late-type infrared galaxies (see e.g., Toffolatti et al 1998;González-Nuevo et al 2005), while the latter are dusty starforming galaxies constituting the cosmic infrared background (CIB; Lagache et al 2005). The contamination due to both types of sources in NG estimators is handled via dedicated bispectrum templates which are fitted jointly with the primordial NG templates.…”

Section: Non-gaussianity From Extragalactic Point Sourcesmentioning

confidence: 99%

Planck2015 results

Ade

Aghanim

Arnaud

et al. 2016

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The Planck full mission cosmic microwave background (CMB) temperature and E-mode polarization maps are analysed to obtain constraints on primordial non-Gaussianity (NG). Using three classes of optimal bispectrum estimators -separable template-fitting (KSW), binned, and modalwe obtain consistent values for the primordial local, equilateral, and orthogonal bispectrum amplitudes, quoting as our final result from temperature alone f local NL = 2.5 ± 5.7, f equil NL = −16 ± 70, and f ortho NL = −34 ± 33 (68% CL, statistical). Combining temperature and polarization data we obtain f local NL = 0.8 ± 5.0, f equil NL = −4 ± 43, and f ortho NL = −26 ± 21 (68% CL, statistical). The results are based on comprehensive cross-validation of these estimators on Gaussian and non-Gaussian simulations, are stable across component separation techniques, pass an extensive suite of tests, and are consistent with estimators based on measuring the Minkowski functionals of the CMB. The effect of time-domain de-glitching systematics on the bispectrum is negligible. In spite of these test outcomes we conservatively label the results including polarization data as preliminary, owing to a known mismatch of the noise model in simulations and the data. Beyond estimates of individual shape amplitudes, we present model-independent, three-dimensional reconstructions of the Planck CMB bispectrum and derive constraints on early universe scenarios that generate primordial NG, including general single-field models of inflation, axion inflation, initial state modifications, models producing parityviolating tensor bispectra, and directionally dependent vector models. We present a wide survey of scale-dependent feature and resonance models, accounting for the "look elsewhere" effect in estimating the statistical significance of features. We also look for isocurvature NG, and find no signal, but we obtain constraints that improve significantly with the inclusion of polarization. The primordial trispectrum amplitude in the local model is constrained to be g local NL = (−9.0 ± 7.7) × 10 4 (68% CL statistical), and we perform an analysis of trispectrum shapes beyond the local case. The global picture that emerges is one of consistency with the premises of the ΛCDM cosmology, namely that the structure we observe today was sourced by adiabatic, passive, Gaussian, and primordial seed perturbations.

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Section: Non-gaussianity From Extragalactic Point Sourcesmentioning

confidence: 99%

Planck2015 results

Ade

Aghanim

Arnaud

et al. 2016

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“…The simulation of their spatial distribution is produced using the method by González-Nuevo et al (2005). Once a map of the source distribution is obtained at the reference frequency ν ref , extrapolations to any other frequency ν i are obtained via the flux-dependent effective spectral…”

Section: Cosmic Infrared Background Anisotropiesmentioning

confidence: 99%

The pre-launchPlanckSky Model: a model of sky emission at submillimetre to centimetre wavelengths

Delabrouille

Betoule

Melin

et al. 2013

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We present the Planck Sky Model (PSM), a parametric model for generating all-sky, few arcminute resolution maps of sky emission at submillimetre to centimetre wavelengths, in both intensity and polarisation. Several options are implemented to model the cosmic microwave background, Galactic diffuse emission (synchrotron, free-free, thermal and spinning dust, CO lines), Galactic H ii regions, extragalactic radio sources, dusty galaxies, and thermal and kinetic Sunyaev-Zeldovich signals from clusters of galaxies. Each component is simulated by means of educated interpolations/extrapolations of data sets available at the time of the launch of the Planck mission, complemented by state-of-the-art models of the emission. Distinctive features of the simulations are spatially varying spectral properties of synchrotron and dust; different spectral parameters for each point source; modelling of the clustering properties of extragalactic sources and of the power spectrum of fluctuations in the cosmic infrared background. The PSM enables the production of random realisations of the sky emission, constrained to match observational data within their uncertainties. It is implemented in a software package that is regularly updated with incoming information from observations. The model is expected to serve as a useful tool for optimising planned microwave and sub-millimetre surveys and testing data processing and analysis pipelines. It is, in particular, used to develop and validate data analysis pipelines within the Planck collaboration. A version of the software that can be used for simulating the observations for a variety of experiments is made available on a dedicated website.

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“…In order to simulate the effect of clustering on the angular power spectrum, we followed the approach described in González-Nuevo et al (2005). We outline here the steps used to create a simulated map where the point sources are clustered according to a chosen angular correlation function.…”

Section: Clustering Of Radio Sourcesmentioning

confidence: 99%

“…In this way we obtained a flat power spectrum for the density field of the sources. Instead of distributing the fluxes of the sources according to the log N log S distribution as done by González-Nuevo et al (2005), we directly normalized the angular power spectrum of the density field to the angular power spectrum of the confusion noise measured in our data. In this way we force the simulated map of point sources to match the observed flux level of the confusion noise.…”

Section: Clustering Of Radio Sourcesmentioning

confidence: 99%

Foregrounds for observations of the cosmological 21 cm line

Bernardi

Bruyn

Harker

et al. 2010

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Context. In the coming years a new insight into galaxy formation and the thermal history of the Universe is expected to come from the detection of the highly redshifted cosmological 21 cm line. Aims. The cosmological 21 cm line signal is buried under Galactic and extragalactic foregrounds which are likely to be a few orders of magnitude brighter. Strategies and techniques for effective subtraction of these foreground sources require a detailed knowledge of their structure in both intensity and polarization on the relevant angular scales of 1-30 arcmin. Methods. We present results from observations conducted with the Westerbork telescope in the 140-160 MHz range with 2 arcmin resolution in two fields located at intermediate Galactic latitude, centred around the bright quasar 3C 196 and the North Celestial Pole. They were observed with the purpose of characterizing the foreground properties in sky areas where actual observations of the cosmological 21 cm line could be carried out. The polarization data were analysed through the rotation measure synthesis technique. We have computed total intensity and polarization angular power spectra. Results. Total intensity maps were carefully calibrated, reaching a high dynamic range, 150 000:1 in the case of the 3C 196 field. No evidence of diffuse Galactic emission was found in the angular power spectrum analysis on scales smaller than ∼10 arcmin in either of the two fields. On these angular scales the signal is consistent with the classical confusion noise of ∼3 mJy beam −1 . On scales greater than 30 arcmin we found an excess of power attributed to the Galactic foreground with an rms of 3.4 K and 5.5 K for the 3C 196 and the NCP field respectively. The intermediate angular scales suffered from systematic errors which prevented any detection. Patchy polarized emission was found only in the 3C 196 field whereas the polarization in the NCP area was essentially due to radio frequency interference. The polarized signal in the 3C 196 field is close to the thermal noise for angular scales smaller than ∼10 arcmin. On scales greater than 30 arcmin it has an rms value of 0.68 K. The polarized signal appears mainly at rotation measure values smaller than 4 rad m −2 . Conclusions. In regard of the detection of the cosmological 21 cm line, we conclude that Galactic total intensity emission lacks small-scale power, which is below the confusion noise level at the angular resolution of 2 arcmin. Galactic polarization, given its relative weakness and its small rotation measure values, is less severe than expected as a contaminant of the cosmological 21 cm line.

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Predictions of the Angular Power Spectrum of Clustered Extragalactic Point Sources at Cosmic Microwave Background Frequencies from Flat and All‐Sky Two‐dimensional Simulations

Cited by 70 publications

References 64 publications

Planck2015 results

Planck2015 results

The pre-launchPlanckSky Model: a model of sky emission at submillimetre to centimetre wavelengths

Foregrounds for observations of the cosmological 21 cm line

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