Cosmological constraints from Archeops

Abstract

We analyze the cosmological constraints that Archeops (Benoît et al. 2003) places on adiabatic cold dark matter models with passive power-law initial fluctuations. Because its angular power spectrum has small bins in ℓ and large ℓ coverage down to COBE scales, Archeops provides a precise determination of the first acoustic peak in terms of position at multipole l_(peak) = 220 ± 6, height and width. An analysis of Archeops data in combination with other CMB datasets constrains the baryon content of the Universe, Ω_bh^2 = 0.022^(+0.003)_(-0.004), compatible with Big-Bang nucleosynthesis and with a similar accuracy. Using cosmological priors obtained from recent non-CMB data leads to yet tighter constraints on the total density, e.g. Ω_(tot) = 1.00^(+0.03)_(-0.02) using the HST determination of the Hubble constant. An excellent absolute calibration consistency is found between Archeops and other CMB experiments, as well as with the previously quoted best fit model. The spectral index n is measured to be 1.04^(+0.10)_(-0.12) when the optical depth to reionization, τ, is allowed to vary as a free parameter, and 0.96^(+0.03)_(-0.04) when τ is fixed to zero, both in good agreement with inflation.

Affiliated Institutions

• Institut des Sciences des Plantes de Paris Saclay FR
• Université Paris Cité FR
• Centre National d'Études Spatiales FR
• Conditions Extrêmes et Matériaux Haute Température et Irradiation FR
• Observatoire Midi-Pyrénées FR
• Jet Propulsion Laboratory US
• Space Research Institute RU
• National University of Ireland, Maynooth IE
• California Institute of Technology US
• Infrared Processing and Analysis Center US
• Collège de France FR
• CEA Paris-Saclay FR
• Laboratoire d'Informatique pour la Mécanique et les Sciences de l'Ingénieur FR
• Direction des énergies FR
• University of Minnesota US
• Laboratoire d’Etudes du Rayonnement et de la Matière en Astrophysique et Atmosphères FR
• Landau Institute for Theoretical Physics RU
• CEA Grenoble FR
• Institut d'Astrophysique Spatiale FR
• Institut d'Astrophysique de Paris FR
• Observatoire de Paris FR
• Astrophysique, Instrumentation et Modélisation FR
• Cardiff University GB
• Université Paris-Saclay FR
• Agence Parisienne du Climat FR
• Commissariat à l'Énergie Atomique et aux Énergies Alternatives FR

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