The Linear Theory Power Spectrum from the Lyα Forest in the Sloan Digital Sky Survey

By P. Mcdonald, Uros Seljak, Renyue Cen, David Shih, D. Weinberg, S. Burles, D. Schneider, David Schlegel, N. Bahcall, J. Briggs and 5 more. 2004

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We analyze the SDSS Lyα forest PF(k, z) measurement to determine the linear theory power spectrum. Our analysis is based on fully hydrodynamic simulations, extended using hydro-particle-mesh simulations. We account for the effect of absorbers with damping wings, which leads to an increase in the slope of the linear power spectrum. We break the degeneracy between the mean level of absorption and the linear power spectrum without significant use of external constraints. We infer linear theory power spectrum amplitude Δ(kp = 0.009 s km-1, zp = 3.0) = 0.452 and slope neff(kp, zp) = -2.321 (possible systematic errors are included through nuisance parameters in the fit: a factor ≳5 smaller errors would be obtained on both parameters if we ignored modeling uncertainties). The errors are correlated and not perfectly Gaussian, so we provide a χ2 table to accurately describe the results. The result corresponds to σ8 = 0.85, n = 0.94 for a ΛCDM model with Ωm = 0.3, Ωb = 0.04, and h = 0.7 but is most useful in a combined fit with the CMB. The inferred curvature of the linear power spectrum and the evolution of its amplitude and slope with redshift are consistent with expectations for ΛCDM models, with the evolution of the slope, in particular, being tightly constrained. We use this information to constrain systematic contamination, e.g., fluctuations in the UV background. This paper should serve as a starting point for more work to refine the analysis, including technical improvements such as increasing the size and number of the hydrodynamic simulations and improvements in the treatment of the various forms of feedback from galaxies and quasars.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/0931213d8db20c3fe5bb3f94163a94dd9448a334

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Citations in the corpus

Modified Gravity and Cosmology (2011, methodology): “Xia considered the generalised model of Dvali and Turner [453] in conjunction with Union SN-Ia data set [733], CMB distance measurements, GRB data [1106], and a collection of data on the growth of linear structure [598, 1248, 1203, 1071, 585, 352, 877].”
Cosmological Constraints from a Combination of Galaxy Clustering and Lensing -- III. Application to SDSS Data (2012, background): “…et al. 2008; Lin et al. 2011), the integrated Sachs-Wolfe effect (e.g., Ho et al. 2008; Giannantonio et al. 2008), the Lyα forest (e.g., Viel, Weller & Haehnelt 2004; McDonald et al. 2005; Desjacques & Nusser 2005), and strong gravitational lensing (e.g., Koopmans et al. 2003; Oguri et al. 2008).”
The Lyman-α forest in three dimensions: measurements of large scale flux correlations from BOSS 1st-year data (2011, methodology): “We use mean transmission fraction approximately matching the observations [8]: ln 〈F 〉 (z) = ln(0.”
A refined measurement of the mean transmitted flux in the Lyα forest over 2 < z < 5 using composite quasar spectra (2012, methodology): “McDonald et al. (2005) also found a relatively smooth evolution of τeff(z) with redshift in a sample of 3035 quasars.”
Constraints on neutrino masses from Lyman-alpha forest power spectrum with BOSS and XQ-100 (2017, methodology): “13 of [43] shows that an increase in the redshift of reionization from z? = 7 to 17 suppresses the Lyα flux power spectrum in the largest k-modes present in the BOSS data (k ∼ 0.”
Lyman-alpha forests cool warm dark matter (2015, methodology): “Finally, we account for any damped Lyman-alpha (DLA) systems we might not have removed in our pipeline by introducing a k-dependent multiplicative correction (see [48] for justification of the analytical form)”
THE BARYON OSCILLATION SPECTROSCOPIC SURVEY OF SDSS-III (2012, background): “The SDSS also obtained the most precise constraints to date on structure at 2 < z < 4 using Lyα forest absorption towards ∼ 3000 high redshift quasars (McDonald et al. 2005, 2006; Seljak et al. 2006), building on earlier studies that analyzed much smaller samples of higher resolution spectra (Croft…”
New Constraints on the free-streaming of warm dark matter from intermediate and small scale Lyman-$\alpha$ forest data (2017, background): “At present, constraints on the matter power spectrum are either derived from moderate size samples with tens of high-resolution, high signal-to-noise spectra (VLT, HIRES/KECK, [7, 9, 12]) or large samples with thousands of low-resolution, low signal-to-noise spectra (SDSS-II, SDSS-III/BOSS, [13, 18,”