Speed from light: growth rate and bulk flow at z ~ 0.1 from improved
  SDSS DR13 photometry
  Observed galaxy luminosities (derived from redshifts) hold information on the
large-scale peculiar velocity field in the form of spatially correlated
scatter, which allows for bounds on bulk flows and the growth rate of matter
density perturbations using large galaxy redshift surveys. We apply this
luminosity approach to galaxies from the recent SDSS Data Release 13. Our goal
is twofold. First, we take advantage of the recalibrated photometry to identify
possible systematic errors relevant to our previous analysis of earlier data.
Second, we seek improved constraints on the bulk flow and the normalized growth
rate f$\sigma_{8}$ at z ~ 0.1. Our results confirm the robustness of our
method. Bulk flow amplitudes, estimated in two redshift bins with 0.02 <
z$_{1}$ < 0.07 < z$_{2}$ < 0.22, are generally smaller than in previous
measurements, consistent with both the updated photometry and expectations for
the $\Lambda$CDM model. The obtained growth rate, f$\sigma_{8}$ = 0.48 +/-
0.16, is larger than, but still compatible with, its previous estimate, and
closer to the reference value of Planck. Rather than precision, the importance
of these results is due to the fact that they follow from an independent method
that relies on accurate photometry, which is a top requirement for
next-generation photometric catalogs.
