Article

The Lyα Forest Power Spectrum from the Sloan Digital Sky Survey

Patrick McDonaldCanadian Institute for Theoretical Astrophysics, University of Toronto, Toronto, ON M5S 3H8, CanadaUroš SeljakPhysics Department, Princeton University, Princeton, NJ 08544Scott BurlesPhysics Department, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139David J. SchlegelLawrence Berkeley National Laboratory, One Cyclotron Road, Mailstop 50R232, Berkeley, CA 94720David H. WeinbergDepartment of Astronomy, The Ohio State University, Columbus, OH 43210Renyue CenPrinceton University Observatory, Princeton, NJ 08544David ShihPhysics Department, Princeton University, Princeton, NJ 08544Joop SchayeSchool of Natural Sciences, Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540Donald P. SchneiderDepartment of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802Neta A. BahcallPrinceton University Observatory, Princeton, NJ 08544John W. BriggsNational Solar Observatory, Sunspot, NM 88349J. BrinkmannApache Point Observatory, 2001 Apache Point Road, Sunspot, NM 88349-0059Róbert BrunnerNCSA and Department of Astronomy, University of Illinois, Urbana, IL 61801M. FukugitaInstitute for Cosmic Ray Research, University of Tokyo, Kashiwa 277-8582, JapanJames E. GunnPrinceton University Observatory, Princeton, NJ 08544Željko IvezićDepartment of Astronomy, University of Washington, Seattle, WA 98195S. KentFermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510Robert H. LuptonPrinceton University Observatory, Princeton, NJ 08544D. E. vanden BerkDepartment of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802

2006en

ABI

Abstract

We measure the power spectrum, P_F(k,z), of the transmitted flux in the Ly-alpha forest using 3035 high redshift quasar spectra from the Sloan Digital Sky Survey. This sample is almost two orders of magnitude larger than any previously available data set, yielding statistical errors of ~0.6% and ~0.005 on, respectively, the overall amplitude and logarithmic slope of P_F(k,z). This unprecedented statistical power requires a correspondingly careful analysis of the data and of possible systematic contaminations in it. For this purpose we reanalyze the raw spectra to make use of information not preserved by the standard pipeline. We investigate the details of the noise in the data, resolution of the spectrograph, sky subtraction, quasar continuum, and metal absorption. We find that background sources such as metals contribute significantly to the total power and have to be subtracted properly. We also find clear evidence for SiIII correlations with the Ly-alpha forest and suggest a simple model to account for this contribution to the power. While it is likely that our newly developed analysis technique does not eliminate all systematic errors in the P_F(k,z) measurement below the level of the statistical errors, our tests indicate that any residual systematics in the analysis are unlikely to affect the inference of cosmological parameters from P_F(k,z). These results should provide an essential ingredient for all future attempts to constrain modeling of structure formation, cosmological parameters, and theories for the origin of primordial fluctuations.

Identifiers

DOI: 10.1086/444361

Citations and references

Cited by 20 references

Metrics — AkademScholar