Detection significance of Baryon Acoustic Oscillations peaks in galaxy and quasar clustering [CEA]

http://arxiv.org/abs/1802.07737


We compare our analysis of the Baryon Acoustic Oscillations (BAO) feature in the correlation functions of SDSS BOSS DR12 LOWZ and CMASS galaxy samples with the findings of arXiv:1509.06371v2. Using subsets of the data we obtain an empirical estimate of the errors on the correlation functions which are in agreement with the simulated errors of arXiv:1509.06371v2. We find that the significance of BAO detection is the quantity most sensitive to the choice of the fitting range with the CMASS value decreasing from 8{\sigma} to 5.3{\sigma} in some cases. Via an F-ratio test, we demonstrate that the A(s) nuisance parameters play a significant role when fitting CMASS and LOWZ correlation functions with the fiducial {\Lambda}CDM model. Although our measurements of DV are in reasonable agreement with those of arXiv:1509.06371v2, we note unexplained issues when fitting with their full covariance which may reduce their estimate of BAO peak significance. We extend our BAO analysis to higher redshifts by fitting to the weighted mean of 2QDESp, SDSS DR5 UNIFORM, 2QZ and 2SLAQ quasar correlation functions, obtaining a 7.7% measurement compared to 3.9% achieved by eBOSS DR14. The larger error on quasar correlation functions implies a smaller role for nuisance parameters in providing a good fit. Although the eBOSS BAO peak significance is only at the 1.4-2.8{\sigma} level, we demonstrate that high-redshift quasars play a vital role in “standard ruler” BAO cosmology.

Read this paper on arXiv…

B. Ansarinejad and T. Shanks
Fri, 23 Feb 18
31/64

Comments: 20 pages, 20 figures, submitted to MNRAS