Speaker
Description
Galaxy clusters and groups are powerful tools for investigating the properties of the Universe. However, the identification of low-redshift X-ray groups remains challenging, requiring deep optical catalogs with reliable redshift estimates over large sky areas. In this work, we aim to detect and characterize galaxy groups through their outskirts by applying an optimized technique that enables the matching of X-ray emission contours with optically identified cluster member galaxies. Taking advantage of the unique characteristics of the S-PLUS survey, we construct tailored volume-limited galaxy group catalogs and explore the population of galaxy groups detected in eROSITA data on spatial scales ranging from 2 to 16 arcminutes. Our preliminary results demonstrate the power of the overlap of more than 2400 square degrees between the two surveys, yielding a catalog of 4618 detections at redshifts z < 0.25. The resulting X-ray luminosity functions illustrate how different matching schemes lead to cluster catalogs with distinct properties, indicating that incompleteness becomes significant below $L_x < 2.5 \times 10^{42}$ erg s$^{-1}$. We find no evidence for matching-induced biases in the luminosity or richness distributions. A comparison of the logN-logS relation with extended X-ray sources reveals an increase of at least a factor of two in the number of matched structures relative to previous studies. This study highlights the potential of S-PLUS, in combination with eROSITA, and the adopted methodologies to provide robust characterizations of galaxy clusters and groups down to low-mass scales, delivering catalogs that will serve as a key reference for systematic studies of galaxy systems and their large-scale environments.