Galaxy bias and σ8 from counts in cells from the SDSS main sample
Abstract
The counts-in-cells (CIC) galaxy probability distribution depends on both the dark matter clustering amplitude σ8 and the galaxy bias b. We present a theory for the CIC distribution based on a previous prescription of the underlying dark matter distribution and a linear volume transformation to redshift space. We show that, unlike the power spectrum, the CIC distribution breaks the degeneracy between σ8 and b on scales large enough that both bias and redshift distortions are still linear; thus, we obtain a simultaneous fit for both parameters. We first validate the technique on the Millennium Simulation and then apply it to the Sloan Digital Sky Survey main galaxy sample. We find σ8 = 0.92 ± .08 and $b = 1.39^{+.11}_{-.09}$ consistent with previous complementary results from redshift distortions and from Planck.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- October 2020
- DOI:
- 10.1093/mnrasl/slaa139
- arXiv:
- arXiv:2006.01146
- Bibcode:
- 2020MNRAS.498L.125R
- Keywords:
-
- surveys;
- cosmological parameters;
- large-scale structure of Universe;
- cosmology: observations;
- Astrophysics - Cosmology and Nongalactic Astrophysics;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 5 pages, 3 figures