Galaxy bias and its effects on the Baryon acoustic oscillations measurements
- Univ. of Arizona, Tucson, AZ (United States)
- Univ. of California, Berkeley, CA (United States); Fermi National Accelerator Lab., Batavia, IL (United States)
- Univ. of Arizona, Tucson, AZ (United States); Harvard Univ., Cambridge, MA (United States)
The baryon acoustic oscillation (BAO) feature in the clustering of matter in the universe serves as a robust standard ruler and hence can be used to map the expansion history of the universe. We use high force resolution simulations to analyze the effects of galaxy bias on the measurements of the BAO signal. We apply a variety of Halo Occupation Distributions (HODs) and produce biased mass tracers to mimic different galaxy populations. We investigate whether galaxy bias changes the non-linear shifts on the acoustic scale relative to the underlying dark matter distribution presented by Seo et al. (2009). For the less biased HOD models (b < 3), we do not detect any shift in the acoustic scale relative to the no-bias case, typically 0.10% ± 0.10%. However, the most biased HOD models (b > 3) show a shift at moderate significance (0.79% ± 0.31% for the most extreme case). We test the one-step reconstruction technique introduced by Eisenstein et al. (2007) in the case of realistic galaxy bias and shot noise. The reconstruction scheme increases the correlation between the initial and final (z = 1) density fields achieving an equivalent level of correlation at nearly twice the wavenumber after reconstruction. Reconstruction reduces the shifts and errors on the shifts. We find that after reconstruction the shifts from the galaxy cases and the dark matter case are consistent with each other and with no shift. The 1σ systematic errors on the distance measurements inferred from our BAO measurements with various HODs after reconstruction are about 0.07%-0.15%.
- Research Organization:
- Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- AC02-07CH11359
- OSTI ID:
- 1013146
- Report Number(s):
- FERMILAB-PUB-11-208-A; arXiv eprint number arXiv:1104.1178; TRN: US1102418
- Journal Information:
- Astrophysical Journal, Vol. 734, Issue 2; ISSN 0004-637X
- Publisher:
- Institute of Physics (IOP)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
ACOUSTICS
BARYONS
DISTRIBUTION
NONLUMINOUS MATTER
OCCUPATIONS
OSCILLATIONS
RESOLUTION
UNIVERSE
astrophysics
distance scale
cosmological parameters
large-scale structure of universe
baryon acoustic oscillations
methods: N-body simulations
cosmology: theory