Brett Hayes, Robert Brunner
We use a quadratic estimator with KL-compression to calculate the angular power spectrum of a volume-limited Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7) galaxy sample out to l = 200. We also determine the angular power spectrum of selected subsamples with photometric redshifts z < 0.3 and 0.3 < z < 0.4 to examine the possible evolution of the angular power spectrum, as well as early-type and late-type galaxy subsamples to examine the relative linear bias. In addition, we calculate the angular power spectrum of the SDSS DR7 main galaxy sample in a ~ 53.7 square degree area out to l = 1600 to determine the SDSS DR7 angular power spectrum to high multipoles. We perform a \chi^2 fit to compare the resulting angular power spectra to theoretical nonlinear angular power spectra to extract cosmological parameters and the linear bias. We find the best-fit cosmological parameters of \Omega_m = 0.267 +- 0.038 and \Omega_b = 0.045 +- 0.012. We find an overall linear bias of b = 1.075 +- 0.056, an early-type bias of b_e = 1.727 +- 0.065, and a late-type bias of b_l = 1.256 +- 0.051. Finally, we present evidence of a selective misclassification of late-type galaxies as stars by the SDSS photometric data reduction pipeline in areas of high stellar density (e.g., at low Galactic latitudes).
View original:
http://arxiv.org/abs/1211.1420
No comments:
Post a Comment