Navegação Ciências Exatas e da Terra por Autor "Rodriguez-Ardila, Alberto"

Resultados 1-20 de 36

    • A 0.8-2.4 μm spectral atlas of active galactic nuclei 

      Riffel, Rogemar André; Rodriguez-Ardila, Alberto; Pastoriza, Miriani Griselda (2006) [Artigo de periódico]
      Aims. We present a near-infrared spectral atlas of 47 active galactic nuclei (AGN) of all degrees of activity in the wavelength interval of 0.8–2.4 μm, including the fluxes of the observed emission lines. We analyze the ...

    • BAT AGN Spectroscopic Survey -IV. : near-infrared coronal lines, hidden broad lines and correlation with hard X-ray emission 

      Lamperti, Isabella; Koss, Michael; Trakhtenbrot, Benny; Schawinski, Kevin; Ricci, Claudio; Oh, Kyuseok; Landt, Hermine; Riffel, Rogério; Rodriguez-Ardila, Alberto; Gehrels, Neil C.; Harrison, Fiona Anne; Masetti, Nicola; Mushotzky, Richard; Treister, Ezequiel; Ueda, Yoshihiro; Veilleux, Sylvain (2017) [Artigo de periódico]
      We provide a comprehensive census of the near-infrared (NIR, 0.8–2.4 μm) spectroscopic properties of 102 nearby (z < 0.075) active galactic nuclei (AGN), selected in the hard X-ray band (14–195 keV) from the Swift-Burst ...

    • Circumnuclear star formation in active galaxies 

      Storchi-Bergmann, Thaisa; Rodriguez-Ardila, Alberto; Schmitt, Henrique Roberto; Wilson, Andrew S.; Baldwin, Jack A. (1996) [Artigo de periódico]
      We study the gas kinematics and chemical abundances in the inner regions of six galaxies with active galactic nuclei. The galaxies were selected for having star-forming regions in rings or spirals within a few kiloparsecs ...

    • A close look at the dwarf AGN of NGC 4395 : optical and near-IR integral field spectroscopy 

      Brum, Carine; Diniz, Marlon Rodrigo; Riffel, Rogemar André; Rodriguez-Ardila, Alberto; Ho, Luis C.; Riffel, Rogério; Mason, Rachel E.; Martins, Lucimara Pires; Petric, Andreea O.; Sanchez-Janssen, Rubén (2019) [Artigo de periódico]
      Intermediate-mass black holes (103–105 M⊙) in the centre of dwarf galaxies are believed to be analogous to growing active galactic nuclei (AGNs) in the early Universe. Their characterization can provide insight about the ...

    • Coronal-line forest active galactic nuclei I. Physical properties of the emission-line regions 

      Campos, Fernando Custodio Cerqueira; Rodriguez-Ardila, Alberto; Riffel, Rogério; Oliveira, Murilo Marinello Assis de; Allende Prieto, Carlos; Hahn, Luis Gabriel Dahmer (2021) [Artigo de periódico]
      Coronal-line forest (CLiF) active galactic nuclei (AGNs) are characterized by strong high-ionization lines, which contrasts with what is found in most AGNs. Here, we carry out a multiwavelength analysis aimed at understanding ...

    • Coronal line forest AGN : II. Analysis of the spectral energy distribution 

      Campos, Fernando Custodio Cerqueira; Rodriguez-Ardila, Alberto; Panda, Swayamtrupta; Riffel, Rogério; Hahn, Luis Gabriel Dahmer; Oliveira, Murilo Marinello Assis de (2023) [Artigo de periódico]
      Coronal-Line Forest Active Galactic Nuclei (CLiF AGN) are characterized by strong, high-ionization lines, which are in contrast to what is found in typical AGNs. Here, we carry out an infrared analysis aimed at understanding ...

    • 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 ...

    • A decade of near-infrared variability in NGC4388 : insights into the AGN structure 

      Hahn, Luis Gabriel Dahmer; Rodriguez-Ardila, Alberto; Bianchin, Marina; Riffel, Rogemar André; Riffel, Rogério; Storchi-Bergmann, Thaisa; Hao, Lei (2023) [Artigo de periódico]
      Variability studies have proven to be a powerful diagnostic tool for understanding the physics and properties of active galactic nuclei (AGNs). They provide insightsinto the spatial and temporal distribution of the emitting ...

    • Differences between CO- and calcium triplet-derived velocity dispersions in spiral galaxies : evidence for central star formation? 

      Riffel, Rogemar André; Ho, Luis C.; Mason, Rachel E.; Rodriguez-Ardila, Alberto; Martins, Lucimara Pires; Riffel, Rogério; Díaz, Rubén Joaquín; Colina, Luis; Alonso-Herrero, Almudena; Flohic, Helene; Gonzalez Martin, Omaira; Lira, Paulina; McDermid, Richard; Ramos Almeida, Cristina; Schiavon, Ricardo P.; Thanjavur, Karun; Dutra, Daniel Ruschel; Winge, Claudia; Perlman, Eric (2015) [Artigo de periódico]
      We examine the stellar velocity dispersions (σ) of a sample of 48 galaxies, 35 of which are spirals, from the Palomar nearby galaxy survey. It is known that for ultra-luminous infrared galaxies (ULIRGs) and merger remnants, ...

    • A Gemini–NIFS view of the merger remnant NGC 34 

      Motter, Juliana Cristina; Riffel, Rogério; Ricci, Tiago Vecchi; Riffel, Rogemar André; Storchi-Bergmann, Thaisa; Pastoriza, Miriani Griselda; Rodriguez-Ardila, Alberto; Dutra, Daniel Ruschel; Hahn, Luis Gabriel Dahmer; Dametto, Natacha Zanon; Diniz, Marlon Rodrigo (2021) [Artigo de periódico]
      The merger remnant NGC 34 is a local luminous infrared galaxy (LIRG) hosting a nuclear starburst and a hard X-ray source associated with a putative, obscured Seyfert 2 nucleus. In this work, we use adaptive optics assisted ...

    • Infrared Fe II emission in narrow-line Seyfert 1 galaxies 

      Rodriguez-Ardila, Alberto; Viegas, Sueli Maria Marino; Pastoriza, Miriani Griselda; Prato, Lisa A. (2002) [Artigo de periódico]
      We obtained 0.8-2.4 μm spectra at a resolution of 320 km s-ˡ of four narrow-line Seyfert 1 galaxies in order to study the near-infrared properties of these objects. We focus on the analysis of the Fe II emission in that ...

    • Molecular hydrogen and [Fe II] in active galactic nuclei 

      Rodriguez-Ardila, Alberto; Pastoriza, Miriani Griselda; Viegas, Sueli Maria Marino; Sigut, T.A.A.; Pradhan, Anil K. (2004) [Artigo de periódico]
      Near-infrared spectroscopy is used to study the kinematics and excitation mechanisms of H2 and [Fe II] lines in a sample of mostly Seyfert 1 galaxies. The spectral coverage allows simultaneous observation of the JHK bands, ...

    • 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 ...

    • Molecular hydrogen and [Fe II] in active galactic nuclei – II. Results for Seyfert 2 galaxies 

      Rodriguez-Ardila, Alberto; Riffel, Rogério; Pastoriza, Miriani Griselda (2005) [Artigo de periódico]
      Near-infrared spectroscopy is used to study the kinematics and excitation mechanisms of H2 and [Fe II] lines in a sample dominated by Seyfert 2 galaxies. The spectra simultaneously cover the JHK bands, allowing us to compare ...

    • Multicolor photometry of ten Seyfert 1 galaxies 

      Boris, Natalia V.; Donzelli, Carlos J.; Pastoriza, Miriani Griselda; Rodriguez-Ardila, Alberto; Ferreiro, Diego L. (2002) [Artigo de periódico]
      We present new valuable BVI photometry of ten Seyfert 1 galaxies and narrow band Hα images for six of these objects. The results indicate that the distribution of the luminosity of the sample has an amplitude of almost 4 ...

    • Near-infrared coronal lines in narrow-line Seyfert 1 galaxies 

      Rodriguez-Ardila, Alberto; Viegas, Sueli Maria Marino; Pastoriza, Miriani Griselda; Prato, Lisa A. (2002) [Artigo de periódico]
      We report spectroscopic observations in the wavelength region 0.8–2.4 μm aimed at detecting near-infrared coronal lines in a sample of five narrow-line and one broad-line Seyfert 1 galaxies. Our measurements show that [Si ...

    • Near-infrared integrated spectra of Galactic globular clusters : testing simple stellar population models 

      Riffel, Rogério; Dutra, Daniel Ruschel; Pastoriza, Miriani Griselda; Rodriguez-Ardila, Alberto; Santos Junior, Joao Francisco Coelho dos; Bonatto, Charles Jose; Ducati, Jorge Ricardo (2011) [Artigo de periódico]
      We present SOAR/OSIRIS cross-dispersed near-infrared (NIR) integrated spectra of 12 Galactic globular clusters that are employed to test Maraston NIR evolutionary population synthesis models, and to provide spectral ...

    • Nuclear and extended spectra of NGC 1068-II. Near-infrared stellar population synthesis 

      Martins, Lucimara Pires; Riffel, Rogério; Rodriguez-Ardila, Alberto; Gruenwald, Ruth B.; Souza, Ronaldo Eustaquio de (2010) [Artigo de periódico]
      We performed stellar population synthesis on the nuclear and extended regions of NGC 1068 by means of near-infrared spectroscopy to disentangle their spectral energy distribution components. This is the first time that ...

    • Optical properties of Peaked Spectrum radio sources 

      Nascimento, Raquel Santiago; Rodriguez-Ardila, Alberto; Hahn, Luis Gabriel Dahmer; Faria, Marcos Antonio Fonseca; Riffel, Rogério; Oliveira, Murilo Marinello Assis de; Beuchert, Tobias; Callingham, Joseph (2022) [Artigo de periódico]
      In this work, we study the optical properties of compact radio sources selected from the literature in order to determine the impact of the radio-jet in their circumnuclear environment. Our sample includes 58 Compact Steep ...

    • Probing evolutionary population synthesis models in the near infrared with early-type galaxies 

      Hahn, Luis Gabriel Dahmer; Riffel, Rogério; Rodriguez-Ardila, Alberto; Martins, Lucimara Pires; Kehrig, Carolina; Heckman, Timothy M.; Pastoriza, Miriani Griselda; Dametto, Natacha Zanon (2018) [Artigo de periódico]
      We performed a near-infrared (NIR; ∼1.0 –2.4 μm) stellar population study in a sample of early-type galaxies. The synthesis was performed using five different evolutionary population synthesis libraries of models. Our main ...