Av. Shishima Hifumi

Oct 15, 2024 | academic.oup.com | Av. Shishima Hifumi |La Plata |Optica y Electronica |Sta. Ma. Tonantzintla

The gas fueling (triggering mechanism) into the supermassive black hole (SMBH) of active galactic nuclei (AGNs) seems to regulate the nuclear star formation activity. This relation, called as AGN-starburst connection, has been investigated through several studies (e.g. Norman & Scoville 1988; Storchi-Bergmann et al. 2000, 2001; Kauffmann et al. 2007; Diamond-Stanic & Rieke 2012; LaMassa et al. 2013).

Oct 15, 2024 | academic.oup.com | Av. Shishima Hifumi |La Plata |Optica y Electronica |Sta. Ma. Tonantzintla

We derive the nitrogen and oxygen abundances in the Narrow Line Regions (NLRs) of a sample of 38 local (z 5) show N/O values in consonance with those derived for local NLRs. This result indicates that the main star-formation event is completed in the early evolution stages of active galaxies.

May 1, 2024 | academic.oup.com | Av. Shishima Hifumi |Instituto de Astronomia

In 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 (3 600 - 10 000 Å) of 40 LINERs from the Mapping Nearby Galaxies (MaNGA) survey were considered. Only objects classified as retired galaxies, i.e. whose main ionization sources are post-Asymptotic Giant Branch (pAGB) stars, were selected.

Dec 19, 2023 | academic.oup.com | Departamento de Astronomía |Instituto de Astronomia |Cidade Universitária |Av. Shishima Hifumi

This paper presents a method for finding ram-pressure stripped (RPS) galaxy candidates by performing a morphological analysis of galaxy images obtained from the Legacy survey. We consider a sample of about 600 galaxies located in different environments such as groups and clusters, tidally interacting pairs and the field. The sample includes 160 RPS previously classified in the literature into classes from J1 to J5, based on the increasing level of disturbances.

Dec 6, 2023 | academic.oup.com | La Plata |Instituto de Física |Instituto de Astronomia |Av. Shishima Hifumi

We analyze the validity of optical diagnostic diagrams relying on emission-lines ratios and in the context of classifying Active Galactic Nuclei (AGNs) according to the cosmic metallicity evolution in the redshift range 0 ≤ z ≤ 11.2. In this regard, we fit the results of chemical evolution models (CEMs) to the radial gradients of the N/O abundances ratio derived through direct estimates of electron temperatures (T -method) in a sample of four local spiral galaxies.