BUSCA POR PROTOAGLOMERADOS NO DARK ENERGY SURVEY COSMOS DEEP FIELD

Abstract

Galaxy clusters are the foundations of large-scale structure, whose abundance and respective masses provide information about the organization of the universe, as well as special environments for galaxy evolution. In this work, data from the Dark Energy Survey, particularly the Deep Fields, were used to search for protocluster candidates, the progenitors of galaxy clusters. Using an algorithm to find galaxy overdensities, we identified potential protocluster candidates in a redshift range from 0.5 to 2.0. Some properties of the candidates and their galaxies-member were explored. The development and validation of the methodology were based on Narwal et al. (2020). We found 176 candidates, and the results were compared to four literature catalogs in the same region as this work. As a result of a 3D match between the catalogs, 150 new candidates were identified that did not match any literature. Only 2 candidates appear in all catalogs, highlighting the inconsistencies between them. We conducted a visual analysis of the 150 new candidates and found 22 candidates with multiple density nuclei, 30 candidates showed a high disproportion between the populations of blue and red galaxies, identified with the Gaussian Mixture Model, and 12 candidates were at the edges of the detection cells of the density map. Nine candidates that showed distortions in the Color-Magnitude Diagram were eliminated. The final number of candidates went from 150 to 141. Morphological studies showed that there is a connection with colors, with bulge-dominated galaxies being redder and more observed at low redshifts. This technique can be applied to future deeper surveys providing targets for spectroscopic follow-up.