Influence of photometric galaxies redshift distribution in BAO estimation (2501.04960v2)

Abstract: Photometric surveys are good solutions for large-scale structure studies. The Baryon Acoustic Oscillations (BAO) benefit from photometric redshift survey observations due to faster coverage and a higher number of observed objects. In the present study, we use the Dark Energy Survey Year 3 catalog of Luminous Red Galaxies (LRG) to incorporate the realistic galaxies' redshift Probability Distribution Function (PDF) into the correlation function cosmological model. We used four different photo-z estimators \texttt{ANNz2}, \texttt{BPZ}, \texttt{ENF}, and \texttt{DNF} to compare how they affect the BAO feature constraint, the catalogs called \texttt{Pz Cats}. Moreover, each algorithm included two sample selections based on distinct PDF shapes; one where the PDFs are nearly Gaussian and another opting for the least noisy PDFs with a pronounced peak. Our investigation identifies whether our samples detect BAO using the correlation function's polynomial parameterization. Later, we computed the correlation function $\xi_\perp(z_p)$ by getting the bin pairs transversal to each other using \texttt{CAMB}. The kernel window function is the $f(z|z_p)$ which is the selection of the PDF value when the photometric redshift is nearly the same as the spectroscopic redshift estimated by the matched spectroscopic sample. For compatible $z_{\rm eff}$, we concluded that the shape of the galaxy redshift PDF could shift the BAO feature position either by including the PDF in the model or not. We also learnt that, given the same spectroscopic sample, \texttt{ANNz2} estimator with its respective selection samples outperforms other estimators for most parameters examined.