Professor Pedro Ferreira

Abstract:

We review selected methods of the Cosmic Microwave Background data analysis appropriate for the analysis of the largest currently available data sets. We focus on techniques of the time-ordered data manipulation and map making algorithms based on the maximum-likelihood approach. The presented methods have been applied to the MAXIMA data analysis (Hanany et al 2000) and the description of the algorithms is illustrated with the examples drawn from that experience. The more extensive presentation of the here-mentioned issues will be given in the forthcoming paper (Stompor et al 2001).

Abstract:

We report the first results from the BOOMERanG experiment, which mapped at 90, 150, 240 and 410 GHz a wide (3%) region of the microwave sky with minimal local contamination. From the data of the best 150 GHz detector we find evidence for a well defined peak in the power spectrum of temperature fluctuations of the Cosmic Microwave Background, localized at $\ell = 197 \pm 6$, with an amplitude of $(68 \pm 8) \mu K_{CMB}$. The location, width and amplitude of the peak is suggestive of acoustic oscillations in the primeval plasma. In the framework of inflationary adiabatic cosmological models the measured spectrum allows a Bayesian estimate of the curvature of the Universe and of other cosmological parameters. With reasonable priors we find $\Omega = (1.07 \pm 0.06)$ and $n_s = (1.00 \pm 0.08)$ (68%C.L.) in excellent agreement with the expectations from the simplest inflationary theories. We also discuss the limits on the density of baryons, of cold dark matter and on the cosmological constant.