Professor Pedro Ferreira

Abstract:

This work describes cosmic microwave background (CMB) data analysis algorithms and their implementations, developed to produce a pixelized map of the sky and a corresponding pixel-pixel noise correlation matrix from time ordered data for a CMB mapping experiment. We discuss in turn algorithms for estimating noise properties from the time ordered data, techniques for manipulating the time ordered data, and a number of variants of the maximum likelihood map-making procedure. We pay particular attention to issues pertinent to real CMB data, and present ways of incorporating them within the framework of maximum likelihood map making. Making a map of the sky is shown to be not only an intermediate step rendering an image of the sky, but also an important diagnostic stage, when tests for and/or removal of systematic effects can efficiently be performed. The case under study is the MAXIMA-I data set. However, the methods discussed are expected to be applicable to the analysis of other current and forthcoming CMB experiments. ©2001 The American Physical Society.

Abstract:

A series of Gaussianity tests were performed on the MAXIMA-1 CMB map. To optimize both the resolution and the signal-to-noise ratio for these tests, a map with 5972 square pixels of 8' each was used. Using these high-quality data, the Gaussianity of CMB anisotropy on subdegree scales was probed for the first time. It was found that the MAXIMA-1 CMB map is consistent with Gaussianity on angular scales between 10 arcmin and 5 deg.

Abstract:

The angular power spectrum of the Cosmic Microwave Background has been measured out to sufficiently small angular scale to encompass a few acoustic oscillations. We use a phenomenological fit to the angular power spectrum to quantify the statistical significance of these oscillations and discuss the cosmological implications of such a finding.