The cosmic microwave background anisotropy power spectrum measured by Archeops

Abstract

We present a determination by the Archeops experiment of the angular power spectrum of the cosmic microwave background anisotropy in 16 bins over the multipole range $\ell=15{-}350$. Archeops was conceived as a precursor of the Planck HFI instrument by using the same optical design and the same technology for the detectors and their cooling. Archeops is a balloon–borne instrument consisting of a 1.5 m aperture diameter telescope and an array of 21 photometers maintained at $\sim 100$ mK that are operating in 4 frequency bands centered at 143, 217, 353 and 545 GHz. The data were taken during the Arctic night of February 7, 2002 after the instrument was launched by CNES from Esrange base (Sweden). The entire data cover ~30% of the sky. This first analysis was obtained with a small subset of the dataset using the most sensitive photometer in each CMB band (143 and 217 GHz) and 12.6% of the sky at galactic latitudes above 30 degrees where the foreground contamination is measured to be negligible. The large sky coverage and medium resolution (better than 15 arcmin) provide for the first time a high signal-to-noise ratio determination of the power spectrum over angular scales that include both the first acoustic peak and scales probed by COBE/DMR. With a binning of $\Delta \ell=7$ to 25 the error bars are dominated by sample variance for $\ell$ below 200. A companion paper details the cosmological implications.

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Affiliated Institutions

• Observatoire Midi-Pyrénées FR
• University of Minnesota US
• Institut National de Physique Nucléaire et de Physique des Particules FR
• Jet Propulsion Laboratory US
• Laboratoire d’Etudes du Rayonnement et de la Matière en Astrophysique et Atmosphères FR
• Landau Institute for Theoretical Physics RU
• Space Research Institute RU
• Campus France FR
• National University of Ireland, Maynooth IE
• California Institute of Technology US
• Istituto per il Rilevamento Elettromagnetico dell'Ambiente IT
• Institut d'Astrophysique Spatiale FR
• Laboratoire de Physique Subatomique et de Cosmologie FR
• Institut d'Astrophysique de Paris FR
• Sapienza University of Rome IT
• Infrared Processing and Analysis Center US
• Cardiff University GB
• GANIL FR
• Institut de Planétologie et d'Astrophysique de Grenoble FR
• Collège de France FR
• Université Bourgogne Franche-Comté FR

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