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arXiv · 2506.08288

A cosmology weakly dependent measurement of 2D Baryon Acoustic Oscillations scale from the Southern Photometric Local Universe Survey

U. Ribeiro·F. Avila·C. R. Bom·C. Franco·A. Cortesi·C. Mendes de Oliveira·A. Kanaan·T. Ribeiro·W. Schoenell·E. Telles·A. Bernui
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Abstract

Baryon Acoustic Oscillations (BAO) provide a robust standard ruler for observational cosmology, enabling precise constraints on the expansion history of the Universe. We present a weakly model-dependent measurement of the BAO angular scale in the low-redshift Universe using the blue galaxies from the Southern Photometric Local Universe Survey (S-PLUS). Our analysis is based on the 2-point angular correlation function applied to a selected photometric sample of $5977$ galaxies with redshifts $0.03 \leq z \leq 0.1$. To account for photometric redshift uncertainties, we implement a resampling technique using the probability distribution function of each galaxy. Angular correlations are computed using the Landy-Szalay estimator; the uncertainties are quantified using a set of $1000$ log-normal mock catalogues. Our 2-point angular correlation analyses reveal a prominent BAO signal that after a shift correction, due to the projection effect caused by the finite thickness of the redshift bin, provides the transversal BAO measurement: $θ_{BAO} = 21.81^{\circ} \pm 0.85^{\circ}$, at $z_{eff} = 0.075$, detected with a statistical significance of $3.22 σ$. In addition, we performed consistency tests that support the robustness of our result. Our measurement constitutes the first robust detection of the transversal BAO scale: at the lowest-redshift in the Universe and using multi-band (narrow+wide) photometry data from the S-PLUS.

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U. Ribeiro, F. Avila, C. R. Bom, C. Franco, A. Cortesi, C. Mendes de Oliveira, A. Kanaan, T. Ribeiro, W. Schoenell, E. Telles, A. Bernui. 2025-06-09. A cosmology weakly dependent measurement of 2D Baryon Acoustic Oscillations scale from the Southern Photometric Local Universe Survey. https://arxiv.org/abs/2506.08288

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