Propriedades morfológicas e rejuvenescimento das populações estelares em galáxias ativas no levantamento MaNGA

• Ano de defesa: 2026
• Autor(a) principal: Weirich, Tiago Henrik Sachet
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Santa Maria; Brasil; UFSM; Programa de Pós-Graduação em Física; Centro de Ciências Naturais e Exatas
• Palavras-chave em Português: Galáxias ativas; Populações estelares; Estrutura de galáxias; Active galaxies; Stellar content; Galaxy structure; CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA
• Link de acesso: http://repositorio.ufsm.br/handle/1/38787

In this work we test whether the selection methoid for control-galaxies, based on matching redshift, mass, and visual morphology, adequately reproduces the structure of galaxies hosting active galactice nuclei (AGN) in the MaNGA survey and whether differences in the stellar populations in the central region (R < 0.5Re) persistss after this matching. For 293 AGN hosts and 492 unique control galaxies, we compare CASGM indices using SDSS r-band images and combine the results with spatially resolved stellar-population light fractions. The control sample was able to replicate the distributions of concentration (C), smoothness/clumpiness (S), Gini (G), and M20, while a small offset was seen in asymmetry (A), with AGN hosts being more asymmetric, as corroborated by tests at fixed C, limiting the difference to a low-amplitude asymmetry. In the central region (R < 0.5Re), although both samples show similar trends, where higher disturbance tracers (A, S, and less negative M20) correspond to a higher fraction of young (xy)(t ≤ 56Myr) and intermediateage (xi)(0.1 ≤ t ≤ 2Gyr) light fractions, while higher C and G follow the older-age (xo)(5 ≤ t ≤ 13Gyr) light fraction, we find that offsets are present across all measured indices for intermediate and old-age fractions, where AGN hosts show a higher fraction of xi and a lower fraction of xo. We interpret that the observed offsets are likely a reflection of a recent circumnuclear rejuvenation event that is not explained by morphological differences between the samples.