Navegação Ciências Exatas e da Terra por Autor "Dors Júnior, Oli Luiz"

Resultados 1-17 de 17

    • Ages and metallicities of circumnuclear star formation regions from Gemini IFU observations 

      Dors Júnior, Oli Luiz; Storchi-Bergmann, Thaisa; Riffel, Rogemar André; Schmidt, Alex Andre (2008) [Artigo de periódico]
      Aims. We derive the age and metallicity of circumnuclear star formation regions (CNSFRs) located in the spiral galaxies NGC6951 and NGC1097 and investigate the cause of the very low equivalent widths of emission lines found ...

    • AGN–starburst connection in NGC 7582 : Gemini near-infrared spectrograph integral field unit observations 

      Riffel, Rogemar André; Storchi-Bergmann, Thaisa; Dors Júnior, Oli Luiz; Winge, Claudia (2009) [Artigo de periódico]
      We analyse two-dimensional near-infrared K-band spectra from the inner 660 × 315 pc² of the Seyfert galaxy NGC7582 obtained with the Gemini near-infrared spectrograph integral field unit at a spatial resolution of ≈50 pc ...

    • Chemical abundances in Seyfert galaxies : IX. Helium abundance estimates 

      Dors Júnior, Oli Luiz; Valerdi, Mabel; Freitas-Lemes, Priscila; Krabbe, Angela Cristina; Riffel, Rogemar André; Amôres, Eduardo Brescansin de; Riffel, Rogério; Armah, Mark; Santos, Adriano Francisco Monteiro dos; Oliveira Junior, Celso Benedito de (2022) [Artigo de periódico]
      For the first time, the helium abundance relative to hydrogen (He/H), which relied on direct measurements of the electron temperature, has been derived in the narrow line regions (NLRs) from a local sample of Seyfert 2 ...

    • Chemical abundances in Seyfert galaxies : VII. Direct abundance determination of neon based on optical and infrared emission lines 

      Armah, Mark; Dors Júnior, Oli Luiz; Aydar, Catarina; Cardaci, Mónica V.; Hägelle, Guillermo Federico; Feltre, Anna; Riffel, Rogério; Riffel, Rogemar André; Krabbe, Angela Cristina (2021) [Artigo de periódico]
      For the first time, neon abundance has been derived in the narrow line region from a sample of Seyfert 2 nuclei. In view of this, we compiled from the literature fluxes of optical and infrared (IR) narrow emission lines ...

    • Chemical abundances in Seyfert galaxies : V. The discovery of shocked emission outside the AGN ionization axis 

      Riffel, Rogemar André; Dors Júnior, Oli Luiz; Armah, Mark; Storchi-Bergmann, Thaisa; Feltre, Anna; Hägelle, Guillermo Federico; Cardaci, Mónica V.; Dutra, Daniel Ruschel; Krabbe, Angela Cristina; Pérez-Montero, Enrique; Zakamska, Nadia L.; Santos, Izabel Cristina Freitas dos (2021) [Artigo de periódico]
      We present maps for the electron temperature in the inner kpc of three luminous Seyfert galaxies: Mrk 79, Mrk 348, and Mrk 607 obtained from Gemini Multi-Object Spectrograph-integral field unit observations at spatial ...

    • Chemical abundances in Seyfert galaxies : X. sulphur abundance estimates 

      Dors Júnior, Oli Luiz; Valerdi, Mabel; Riffel, Rogemar André; Riffel, Rogério; Cardaci, Mónica V.; Hägelle, Guillermo Federico; Armah, Mark; Revalski, Mitchell; Flury, Sophia; Freitas-Lemes, Priscila; Amôres, Eduardo Brescansin de; Krabbe, Angela Cristina; Binette, Luc; Feltre, Anna; Storchi-Bergmann, Thaisa (2023) [Artigo de periódico]
      For the first time, the sulphur abundance relative to hydrogen (S/H) in the narrow-line regions of a sample of Seyfert 2 nuclei (Sy 2s) has been derived via direct estimation of the electron temperature. Narrow emission-line ...

    • Circumnuclear star formation in Mrk 42 mapped with Gemini Near-infrared Integral Field Spectrograph 

      Hennig, Moiré Gonçalves; Riffel, Rogemar André; Dors Júnior, Oli Luiz; Riffel, Rogério; Storchi-Bergmann, Thaisa; Colina, Luis (2018) [Artigo de periódico]
      We present Gemini Near-infrared Integral Field Spectrograph (NIFS) observations of the inner 1.5 × 1.5 kpc2 of the narrow-line Seyfert 1 galaxy Mrk 42 at a spatial resolution of 60 pc and spectral resolution of 40 kms−1. ...

    • A correlation between the stellar and [Fe II] velocity dispersions in active galaxies 

      Riffel, Rogemar André; Storchi-Bergmann, Thaisa; Riffel, Rogério; Pastoriza, Miriani Griselda; Rodriguez-Ardila, Alberto; Dors Júnior, Oli Luiz; Fuchs, Jaciara Tamara; Diniz, Marlon Rodrigo; Schönell Júnior, Astor João; Hennig, Moiré Gonçalves; Brum, Carine (2013) [Artigo de periódico]
      We use near-infrared (near-IR) spectroscopic data from the inner few hundred parsecs of a sample of 47 active galaxies to investigate possible correlations between the stellar velocity dispersion (σ ), obtained from the ...

    • Gas-phase metallicity determinations in nearby AGNs with SDSS-IV MaNGA : evidence of metal-poor accretion 

      Nascimento, Janaina Correa do; Dors Júnior, Oli Luiz; Storchi-Bergmann, Thaisa; Mallmann, Nícolas Dullius; Riffel, Rogério; Ilha, Gabriele da Silva; Riffel, Rogemar André; Rembold, Sandro Barboza; Machado, Alice Deconto; Costa, Luiz N. da; Armah, Mark (2022) [Artigo de periódico]
      We derive the metallicity (traced by the O/H abundance) of the narrow-line region (NLR) of 108 Seyfert galaxies as well as radial metallicity gradients along their galaxy discs and of these of a matched control sample of ...

    • Interaction effects on galaxy pairs with Gemini/GMOS- I : electron density 

      Krabbe, Angela Cristina; Rosa, Deise Aparecida; Dors Júnior, Oli Luiz; Pastoriza, Miriani Griselda; Winge, Claudia; Hägelle, Guillermo Federico; Cardaci, Mónica V.; Rodrigues, Irapuan (2014) [Artigo de periódico]
      We present an observational study about the impacts of the interactions on the electron density of HII regions located in seven systems of interacting galaxies. The data consist of long-slit spectra in the range 4400–7300 ...

    • Interaction effects on galaxy pairs with Gemini/GMOS- III : stellar population synthesis 

      Krabbe, Angela Cristina; Rosa, Deise Aparecida; Pastoriza, Miriani Griselda; Hägelle, Guillermo Federico; Cardaci, Mónica V.; Dors Júnior, Oli Luiz; Winge, Claudia (2017) [Artigo de periódico]
      We present an observational study of the impacts of interactions on the stellar population in a sample of galaxy pairs. Long-slit spectra in the wavelength range 3440–7300 Å obtained with the Gemini Multi-Object Spectrograph ...

    • Interaction effects on galaxy pairs with Gemini/GMOS – II oxygen abundance gradients 

      Rosa, Deise Aparecida; Dors Júnior, Oli Luiz; Krabbe, Angela Cristina; Hägelle, Guillermo Federico; Cardaci, Mónica V.; Pastoriza, Miriani Griselda; Rodrigues, Irapuan; Winge, Claudia (2014) [Artigo de periódico]
      In this paper, we derive oxygen abundance gradients from HII regions located in 11 galaxies in eight systems of close pairs. Long-slit spectra in the range 4400–7300 Å were obtained with the Gemini Multi-Object Spectrograph ...

    • Molecular hydrogen and [Fe II] in active galactic nuclei – III. Low-ionization nuclear emission-line region and star-forming galaxies 

      Riffel, Rogério; Rodriguez-Ardila, Alberto; Aleman, Isabel Regina Guerra; Brotherton, Mike; Pastoriza, Miriani Griselda; Bonatto, Charles Jose; Dors Júnior, Oli Luiz (2013) [Artigo de periódico]
      We study the kinematics and excitation mechanisms of H2 and [Fe II] lines in a sample of 67 emission-line galaxies with Infrared Telescope Facility SpeX near-infrared (0.8–2.4 μm) spectroscopy together with new photoionization ...

    • Nuclear spirals as feeding channels to the supermassive black hole : the case of the galaxy NGC 6951 

      Storchi-Bergmann, Thaisa; Dors Júnior, Oli Luiz; Riffel, Rogemar André (2007) [Artigo de periódico]
      We report the discovery of gas streaming motions along nuclear spiral arms toward the LINER nucleus of the galaxyNGC 6951. The observations, obtained using theGMOS integral field spectrograph on the Gemini North telescope, ...

    • Optical and mid-infrared neon abundance determinations in star-forming regions 

      Dors Júnior, Oli Luiz; Hägelle, Guillermo Federico; Cardaci, Mónica V.; Pérez-Montero, Enrique; Krabbe, Angela Cristina; Vilchez, Jose M.; Sales, Dinalva Aires de; Riffel, Rogério; Riffel, Rogemar André (2013) [Artigo de periódico]
      We have used observational spectroscopic data of star-forming regions compiled from the literature and photoionization models to analyse the neon ionic abundances obtained using both optical and mid-infrared emission lines. ...

    • Oxygen abundances in the narrow line regions of Seyfert galaxies and the metallicity–luminosity relation 

      Armah, Mark; Riffel, Rogério; Dors Júnior, Oli Luiz; Oh, Kyuseok; Koss, Michael; Ricci, Claudio; Trakhtenbrot, Benny; Valerdi, Mabel; Riffel, Rogemar André; Krabbe, Angela Cristina (2023) [Artigo de periódico]
      We present oxygen abundances relative to hydrogen (O/H) in the narrow line regions (NLRs) gas phases of Seyferts 1 (Sy 1s) and Seyferts 2 (Sy 2s) active galactic nuclei (AGNs). We used fluxes of the optical narrow emission ...

    • The effects of the interactions on the kinematics, stellar population and metallicity of AM2322−821 with Gemini/GMOS 

      Krabbe, Angela Cristina; Pastoriza, Miriani Griselda; Winge, Claudia; Rodrigues, Irapuan; Dors Júnior, Oli Luiz; Ferreiro, Diego L. (2011) [Artigo de periódico]
      We present an observational study of the impacts of the interactions on the kinematics, stellar populations and oxygen abundances of the components of the galaxy pair AM2322−821. A fairly symmetric rotation curve for the ...