Navegação por Assunto "ISM: abundances"

Resultados 1-6 de 6

    • 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 ...

    • 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 ...

    • Estimating stellar birth radii and the time evolution of Milky Way’s ISM metallicity gradient 

      Minchev, Ivan; Anders, Friedrich; Recio-Blanco, Alejandra; Chiappini, C.C.M.; Laverny, Patrick de; Queiroz, Anna Bárbara de Andrade; Steinmetz, M.; Adibekyan, Vardan; Carrillo, Ismael; Cescutti, Gabriele; Guiglion, Guillaume; Hayden, Michael; Jong, Roelof S. de; Kordopatis, Georges; Majewski, Steven Raymond; Martig, Marie; Santiago, Basilio Xavier (2018) [Artigo de periódico]
      We present a semi-empirical, largelymodel-independent approach for estimatingGalactic birth radii, rbirth, for Milky Way disc stars. The technique relies on the justifiable assumption that a negative radial metallicity ...

    • 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 ...

    • Long-slit spectrophotometry of the H II regions Gum 38a and Gum 38b 

      Girardi, Leo Alberto; Bica, Eduardo Luiz Damiani; Pastoriza, Miriani Griselda; Winge, Claudia (1997) [Artigo de periódico]
      We present new long-slit spectrophotometric observations in the range 3700-7200 Å of the H II regions Gum 38a and Gum 38b (RCW 57). We study the spatial distribution of reddenig ad excitation throughout the complex by means ...

    • A new hot DA white dwarf in a region of exceptionally low HI density 

      Barstow, Martin A.; Wesemael, F.; Holberg, J.B.; Buckley, David A.H.; Stobie, Robert S.; Mittaz, J.P.D.; Fontaine, Gilles; Rosen, Simon R.; Demers, Serge; Lamontagne, R.; Irwin, Michael John; Bergeron, Pierre; Kepler, Souza Oliveira; Vennes, S. (1994) [Artigo de periódico]
      We report the discovery of the hot DA white dwarf RE 0457- 281 which has the lowest line-of-sight neutral hydrogen column density yet measured. The star was found independently by the ROSAT EUV, Montreal-Cambridge-Tololo ...