Searching for non Gaussian signals in the BOOMERanG 2003 CMB maps

TL;DR

This paper analyzes BOOMERanG 2003 CMB maps to constrain primordial non-Gaussianity, finding results consistent with Gaussian fluctuations and setting new limits on the non-linear coupling parameter f_NL.

Contribution

First application of Minkowski functionals to BOOMERanG data to limit primordial non-Gaussianity, providing the most stringent constraints from this dataset.

Findings

Results consistent with Gaussian fluctuations

First limits on f_NL from BOOMERanG data

Constraints: -300<f_NL<650 at 68% CL

Abstract

We analyze the BOOMERanG 2003 (B03) 145 GHz temperature map to constrain the amplitude of a non Gaussian, primordial contribution to CMB fluctuations. We perform a pixel space analysis restricted to a portion of the map chosen in view of high sensitivity, very low foreground contamination and tight control of systematic effects. We set up an estimator based on the three Minkowski functionals which relies on high quality simulated data, including non Gaussian CMB maps. We find good agreement with the Gaussian hypothesis and derive the first limits based on BOOMERanG data for the non linear coupling parameter f_NL as -300<f_NL<650 at 68% CL and -800<f_NL<1050 at 95% CL.