A Comparative Photometric Study of Nearby Galaxy Groups and Clusters

• Grant number: 25/05085-1
• Support Opportunities: Research Grants - Visiting Researcher Grant - International
• Start date: June 15, 2025
• End date: December 14, 2025
• Field of knowledge: Physical Sciences and Mathematics - Astronomy - Extragalactic Astrophysics
• Principal Investigator: Angela Cristina Krabbe
• Grantee: Angela Cristina Krabbe
• Visiting researcher: Analia Viviana Smith Castelli
• Visiting researcher institution: Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
• Host Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

In the context of the S-PLUS Fornax Project, a new SExtractor photometry for galaxies different from that provided by the data releases of S-PLUS was obtained for the Fornax cluster galaxies, tailored for obtaining precise photometry for large and bright galaxies. This has allowed a number of studies of this cluster, from the analysis of the structure of the galaxies to the determination of their stellar population parameters and the determination of the substructures in the cluster. Given the good results for the Fornax cluster, in this project we plan to obtain the same photometry for nearby galaxy groups and clusters already observed with S-PLUS displaying z < 0.019, for which the Halpha line is within the Halpha filter. Examples of such clusters are Antlia, Hydra, Abell 194 and the Dorado group. From that homogeneous and specific photometry, we plan to quantify morphological differences in the different environments, for example, making a large-scale analysis of several photometric properties like effective radius and colors of the galaxies, and non-parametric analysis using parameters such as asymmetry, concentration,Gini index, among others, obtained using the code astromorphlib developed within our group (Krabbe et al. 2023). We also plan to analyze the characteristics of the stellar populations both for the galaxies as a whole and pixel by pixel, producing large-scale and galaxy-internal spatial distributions depicted in maps of mass, extinction, emission ([OII], Halpha+[NII], Halpha, etc). Applying different clustering algorithms, it will also be possible to identify internal substructures in all the analyzed groups and clusters. The main goal of such comparative analysis will be to try to identify common processes driving galaxy formation and evolution in nearby and dense environments. In order to set control samples for the different studies, we also plan to include in this analysis the outskirts areas of the analyzed groups and clusters. (AU)