J. Delabrouille

A full sky, low foreground, high resolution CMB map from WMAP

Context. The WMAP satellite has made available high quality maps of the sky in five frequency bands ranging fromxa022 to 94xa0GHz, with the main scientific objective of studying the anisotropies of the Cosmic Microwave Background (CMB). These maps, however, contain a mixture of emission from various astrophysical origin, superimposed on CMBxa0emission. Aims. The objective of the present work is to make a high resolution CMBxa0map in which contamination by such galactic and extra-galactic foreground emissions, as well as by instrumental noise, is as low as possible. Methods. The method used is an implementation of a constrained linear combination of the channels with minimum error variance, and of Wiener filtering, on a frame of spherical wavelets called needlets, allowing localised filtering in both pixel space and harmonic space. Results. We obtain a low contamination low noise CMBxa0map at the resolution of the WMAP W channel, which can be used for a range of scientific studies. We obtain also a Wiener-filtered version with minimal integrated error. Conclusions. The resulting CMB maps offer significantly better rejection of galactic foreground than previous CMB maps from WMAPxa0data. They can be considered as the most precise full-sky CMB temperature maps to date.

Calibration and first light of the Diabolo photometer at the Millimetre and Infrared Testa Grigia Observatory

We have designed and built a large-throughput dual channel photometer, Diabolo. This photometer is dedicated to the observation of millimetre continuum diffuse sources, and in particular, of the Sunyaev-Zeldovich effect and of anisotropies of the 3 K background. We describe the optical layout and filtering system of the instrument, which uses two bolometric detectors for simultaneous observations in two frequency channels at 1.2 and 2.1 mm. The bolometers are cooled to a working temperature of

Planck intermediate results IX

0.1 rm,K