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Open Access Publications from the University of California

The one-dimensional Lyαforest power spectrum from BOSS

  • Author(s): Palanque-Delabrouille, Nathalie
  • Yèche, Christophe
  • Borde, Arnaud
  • Le Goff, Jean-Marc
  • Rossi, Graziano
  • Viel, Matteo
  • Aubourg, Éric
  • Bailey, Stephen
  • Bautista, Julian
  • Blomqvist, Michael
  • Bolton, Adam
  • Bolton, James S
  • Busca, Nicolás G
  • Carithers, Bill
  • A. C. Croft, Rupert
  • Dawson, Kyle S
  • Delubac, Timothée
  • Font-Ribera, Andreu
  • Ho, Shirley
  • Kirkby, David
  • Lee, Khee-Gan
  • Margala, Daniel
  • Miralda-Escudé, Jordi
  • Muna, Demitri
  • Myers, Adam D
  • Noterdaeme, Pasquier
  • Pâris, Isabelle
  • Petitjean, Patrick
  • Pieri, Matthew M
  • Rich, James
  • Rollinde, Emmanuel
  • Ross, Nicholas P
  • Schlegel, David J
  • Schneider, Donald P
  • Slosar, Anže
  • Weinberg, David H
  • et al.

We have developed two independent methods for measuring the one-dimensional power spectrum of the transmitted flux in the Lyman-α forest. The first method is based on a Fourier transform and the second on a maximum-likelihood estimator. The two methods are independent and have different systematic uncertainties. Determination of the noise level in the data spectra was subject to a new treatment, because of its significant impact on the derived power spectrum. We applied the two methods to 13 821 quasar spectra from SDSS-III/BOSS DR9 selected from a larger sample of over 60 000 spectra on the basis of their high quality, high signal-to-noise ratio (S/N), and good spectral resolution. The power spectra measured using either approach are in good agreement over all twelve redshift bins from 〈z〉 = 2.2 to 〈z〉 = 4.4, and scales from 0.001 km s -1 to 0.02 km s -1 . We determined the methodological andinstrumental systematic uncertainties of our measurements. We provide a preliminary cosmological interpretation of our measurements using available hydrodynamical simulations. The improvement in precision over previously published results from SDSS is a factor 2-3 for constraints on relevant cosmological parameters. For a ΛCDM model and using a constraint on H 0 that encompasses measurements based on the local distance ladder and on CMB anisotropies, we infer σ 8 = 0.83 ± 0.03 and n s = 0.97 ± 0.02 based on Hi absorption in the range 2.1 < z < 3.7. © ESO, 2013.

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