Archeops: A CMB anisotropy balloon experiment measuring a broad range of angular scales

¹ Laboratoire d'Astrophysique, Observatoire de Grenoble, BP. 53, 414 rue de la piscine, 38041 Grenoble Cedex 9, France
² From the following institutes: California, Institute of Technology, Pasadena, USA Centre d'Étude Spatiale des Rayonnements, Toulouse, France Centre de spectrométrie nucléaire et de spectrométrie de masse, Orsay, France Collège de France, Paris, France DAPNIA CEA, Saclay, France Institut d'Astrophysique de Paris, Paris, France Institut d'Astrophysique Spatiale, Orsay, France Institut des Sciences Nucléaires de Grenoble, Grenoble, France IROE CNR, Firenze, Italy Jet Propulsion Laboratory, Pasadena, USA Laboratoire de l'accélérateur linéaire, Orsay, France Landau Institute of Theoretical Physics, Moscow, Russia Observatoire Midi-Pyrénées, Toulouse, France Queen Mary and Westfield College, London, UK Universita di Roma La Sapienza, Roma, Italy University of Minnesota at Minneapolis, USA

Abstract

The Cosmic Microwave Background Radiation is the oldest photon radiation that can be observed, having been emitted when the Universe was about 300 000 year old. It is a blackbody at 2.73 K, and is almost perfectly isotropic, the anisotropies being about one part to 100 000. However, these anisotropies, detected by the COBE satellite in 1992, constrain the cosmological parameters such as the curvature of the Universe. Archeops is a balloon-borne experiment designed to map these anisotropies. The instrument is composed of a 1.5 m telescope and bolometers cooled at 85 mK to detect radiation between 150 and 550 GHz. To lower parasitic signals, the instrument is borne by a stratospheric balloon during the arctic night. This instrument is also a preparation for the Planck satellite mission, as its design is similar to HFI. We discuss here the results of the first scientific flight from Esrange (near Kiruna, Sweden) to Russia on January 29th 2001, which led to a 22% (sub)millimetre sky coverage unprecedented at this resolution. Here, we put some emphasis on interstellar dust foreground emission observations.