2023/06/02 by Keitaro Ishikawa, Ishikawa, Keitaro, Tomomi Sunayama +6 · 1 citation
Economics, Econometrics and Finance · #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #Monetary Policy and Economic Impact
paper · pdf · doi:10.48550/arxiv.2306.01696
openalex publication_date 2023/06/02 · openalex created_date 2023/06/07 · openalex updated_date 2026/07/28
We investigate the robustness of baryon acoustic oscillations (BAO) measurements with a photometric galaxy sample using mock galaxy catalogues with various sizes of photometric redshift (photo-z) uncertainties. We first conduct the robustness of BAO measurements, assuming we have a perfect knowledge of photo-z uncertainties. We find that the BAO shift parameter α can be constrained in an unbiased manner even for 3% photometric redshift uncertainties up to z∼ 1. For instance, α=1.006 ± 0.078 with 95% confidence level is obtained from 3% photo-z uncertainty data at z=1.03 using the sample of M_* ≥ 1010.25 M\odot/h2. We also find that a sparse galaxy sample, e.g. <2×10-4 [h Mpc-1]3 causes additional noise in the covariance matrix calculation and can bias the constraint on α. Following this, we look into the scenario where incorrect photometric redshift uncertainties are assumed in the fitting model. We find that underestimating the photo-z uncertainty leads to a degradation in the constraining power on α. However, the constrained value of α is not biased. We also quantify the constraining power on Ω\rm m0 assuming the LSST-like covariance and find that the 95% confidence level is σ(Ω\rm m0)∼0.03-0.05 corresponding to the photo-z uncertainties of 1% to 3% respectively. Finally, we examine whether the skewness in the photometric redshift can bias the constraint on α and confirm that the constraint on α is unbiased, even assuming a Gaussian photo-z uncertainty in our model.