The forthcoming Planck experiment will provide high sensitivity polarization measurements that will allow us to further tighten the fNL bounds from the temperature data. Monte Carlo simulations of non-Gaussian cosmic microwave background maps have been used as a fundamental tool to characterize non-Gaussian signatures in the data, as they allow us to calibrate any statistical estimators and understand the effect of systematics, foregrounds and other contaminants. We describe an algorithm to generate high-angular resolution simulations of non-Gaussian cosmic microwave background maps in temperature and polarization. We consider non-Gaussianities of the local type, for which the level of non-Gaussianity is defined by the dimensionless parameter, fNL. We then apply the temperature and polarization fast cubic statistics recently developed by Yadav et al. to a set of non-Gaussian temperature and polarization simulations. We compare our results to theoretical expectations based on a Fisher matrix analysis, test the unbiasedness of the estimator, and study the dependence of the error bars on fNL. All our results are in very good agreement with theoretical predictions, thus confirming the reliability of both the simulation algorithm and the fast cubic temperature and polarization estimator.

Temperature and Polarization CMB Maps from Primordial Non-Gaussianities of the Local Type

LIGUORI, MICHELE;MATARRESE, SABINO;
2007

Abstract

The forthcoming Planck experiment will provide high sensitivity polarization measurements that will allow us to further tighten the fNL bounds from the temperature data. Monte Carlo simulations of non-Gaussian cosmic microwave background maps have been used as a fundamental tool to characterize non-Gaussian signatures in the data, as they allow us to calibrate any statistical estimators and understand the effect of systematics, foregrounds and other contaminants. We describe an algorithm to generate high-angular resolution simulations of non-Gaussian cosmic microwave background maps in temperature and polarization. We consider non-Gaussianities of the local type, for which the level of non-Gaussianity is defined by the dimensionless parameter, fNL. We then apply the temperature and polarization fast cubic statistics recently developed by Yadav et al. to a set of non-Gaussian temperature and polarization simulations. We compare our results to theoretical expectations based on a Fisher matrix analysis, test the unbiasedness of the estimator, and study the dependence of the error bars on fNL. All our results are in very good agreement with theoretical predictions, thus confirming the reliability of both the simulation algorithm and the fast cubic temperature and polarization estimator.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11577/1775021
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