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 $0.03\le z\le 0.1$. 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 catalogs. 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: ${\theta }_{\mathrm{BAO}}=20.41°\pm 2.14°$, at $z_{\mathrm{eff}}=0.075$, detected with a statistical significance of $1.50\sigma$. 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 multiband ($\mathrm{narrow}+\mathrm{wide}$) photometry data from the S-PLUS.

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• Baryon acoustic oscillations
• Optical, UV, & IR astronomy
• Sky surveys