Acoustic oscillations in the SDSS DR4 luminous red galaxy sample power spectrum

Abstract

We calculate the redshift-space power spectrum of the Sloan Digital Sky Survey (SDSS) Data Release 4 (DR4) Luminous Red Galaxy (LRG) sample, finding evidence for a full series of acoustic features down to the scales of ~$0.2\,h\,{\rm Mpc}^{-1}$. This corresponds to the 7th peak in the CMB angular power spectrum. The acoustic scale derived, $(105.4 \pm 2.3)\,h^{-1}\,{\rm Mpc}$, agrees very well with the “concordance” model prediction and also with the one determined via the analysis of the spatial two-point correlation function by Eisenstein et al. (2005, ApJ, 633, 560). The models with baryonic features are favored by $3.3 \sigma$ over their “smoothed” counterparts without any oscillatory behavior. This is not only an independent confirmation of results by Eisenstein et al. (2005), made with different methods and software but also, to our knowledge, is the first determination of the power spectrum of the SDSS LRG sample.