Oliveira Junior, Celso B.Krabbe, Angela CristinaDors Junior, Oli LuizZinchenko, IgorHernandez-Jimenez, Jose AndresCardaci, Mónica VivianaHagele, Guillermo F.Ilha, Gabriele da Silva2025-01-302025-01-30https://repositorio.univap.br/handle/123456789/533In this work, we investigated the nitrogen and oxygen abundances in a sample of galaxies with Low Ionization Nuclear Emission Regions (LINERs) in their nucleus. Optical spectroscopic data (3600 – 10 000 Å) of 40 LINERs from the Mapping Nearby Galaxies (MaNGAs) survey were considered. Only objects classified as retired galaxies, that is, whose main ionization sources are post-Asymptotic Giant Branch (pAGB) stars, were selected. The abundance estimates were obtained through detailed photoionization models built with the CLOUDY code to reproduce a set of observational emission line intensities ratios of the sample. Our results show that LINERs have oxygen and nitrogen abundances in the ranges of 8.0 􏰀 12 + log(O/H) 􏰀 9.0 (mean value 8.74 ± 0.27) and 7.6 􏰀 12 + log(N/H) 􏰀 8.5 (mean value 8.05 ± 0.25), respectively. About 70 per cent of the sample have oversolar O/H and N/H abundances. Our abundance estimates are in consonance with those for Seyfert 2 nuclei and H II regions with the highest metallicity, indicating that these distinct object classes show similar enrichment of the interstellar medium (ISM). The LINERs in our sample are located in the higher N/O region of the N/O versus O/H diagram, showing an unexpected negative correlation between these two parameters. These results suggest that these LINERs mainly exhibit a secondary nitrogen production and could be acting some other mechanisms that deviate them from the usual theoretical secondary nitrogen production curve and the H II regions observations. However, we did not find any evidence in our data able to support the literature suggested mechanisms. Alternatively, our results show that LINERs do not present any correlation between the N/O abundances and the stellar masses of the hosting galaxies.PDFen-USArtigos de PeriódicosCelso B. Oliveira JuniorAngela Cristina KrabbeOli Luiz Dors JuniorIgor ZinchenkoJose Andres Hernandez JimenezMónica Viviana CardaciGuillermo F. HageleGabriele da Silva Ilha10.1093/mnras/stae1172GalaxiesNitrogen abundanceOliveira, C. B. et al. Chemical abundances of LINER galaxies – nitrogen abundance estimations. Monthly Notices of the Royal Astronomical Society, v. 531, n. 1, p. 199–212, 2024.Universidade do Vale do ParaíbaLudwig Maximilians UniversitätInstituto de Astrofísica de La Plata (CONICET–UNLP)Universidade de São Paulo