Navegação Ciências Exatas e da Terra por Assunto "Galaxies: nuclei"

Resultados 81-100 de 104

    • Study of the nuclei of NGC 3732 and IC 4662 

      Pastoriza, Miriani Griselda; Dottori, Horacio Alberto (1981) [Artigo de periódico]
      The nuclei of two galaxies which show intense [O III] emission lines, NGC 3732, an Sa, and IC 4662, an irregular with a very bright nucleus, are analyzed spectroscopically. The physical condition of the emitting gas and ...

    • The black hole mass of NGC 4151. II. Stellar dynamical measurement from near-infrared field spectroscopy 

      Onken, Christopher Alan; Valluri, Monica; Brown, Jonathan S.; McGregor, Peter J.; Peterson, Bradley M.; Bentz, Misty Cherie; Ferrarese, Laura; Pogge, Richard William; Vestergaard, Marianne; Storchi-Bergmann, Thaisa; Riffel, Rogemar André (2014) [Artigo de periódico]
      We present a revised measurement of themass of the central black hole (MBH ) in the Seyfert 1 galaxyNGC4151. The new stellar dynamical mass measurement is derived by applying an axisymmetric orbit-superposition code to ...

    • The CaT strength in Seyfert nuclei revisited : analysing young stars and non-stellar light contributions to the spectra 

      Neme, Luis Rodolfo Vega; Asari, Natalia Vale; Fernandes Junior, Roberto Cid; Garcia-Rissmann, Aurea; Storchi-Bergmann, Thaisa; González Delgado, Rosa M.; Schmitt, Henrique Roberto (2009) [Artigo de periódico]
      In a former paper, we have presented spectra of 64 active, nine normal and five starburst galaxies in the region around the near-infrared calcium triplet (CaT) absorption lines and the [S III]λ9069 line. In the present ...

    • The complex gas kinematics in the nucleus of the Seyfert 2 galaxy NGC 1386 : rotation, outflows, and inflows 

      Lena, Davide; Robinson, Andrew; Storchi-Bergmann, Thaisa; Müller, Allan Schnorr; Seelig, T.; Riffel, Rogemar André; Nagar, Neil M.; Couto, Guilherme dos Santos; Shadler, l (2015) [Artigo de periódico]
      We present optical integral field spectroscopy of the circum-nuclear gas of the Seyfert 2 galaxy NGC 1386. The data cover the central 7″ × 9″ (530 × 680 pc) at a spatial resolution of 0″. 9 (68 pc), and the spectral range ...

    • The dusty nuclear torus in NGC 4151 : constraints from gemini near-infrared integral field spectrograph observations 

      Riffel, Rogemar André; Storchi-Bergmann, Thaisa; McGregor, Peter J. (2009) [Artigo de periódico]
      We have used a near-infrared (near-IR) nuclear spectrum (covering the Z, J, H, and K bands) of the nucleus of NGC 4151 obtained with the Gemini Near-Infrared Integral Field Spectrograph (NIFS) and adaptive optics, to isolate ...

    • The Eddington ratio-dependent ‘changing look’ events in NGC 2992 

      Pereira, Muryel Guolo; Dutra, Daniel Ruschel; Grupe, Dirk; Peterson, Bradley M.; Storchi-Bergmann, Thaisa; Schimoia, Jáderson da Silva; Nemmen, Rodrigo S.; Robinson, Andrew (2021) [Artigo de periódico]
      We present an analysis of historical multiwavelength emission of the `Changing Look’ (CL) Active Galactic Nucleu (AGN) in NGC 2992, covering epochs ranging from 1978 to 2021, as well as new X-ray and optical spectra. The ...

    • The first detection of near-infrared CN bands in active galactic nuclei : signature of star formation 

      Riffel, Rogemar André; Pastoriza, Miriani Griselda; Rodriguez-Ardila, Alberto; Maraston, Claudia (2007) [Artigo de periódico]
      We present the first detection of the near-infrared CN absorption band in the nuclear spectra of active galactic nuclei (AGNs). This feature is a recent star formation tracer, being particularly strong in carbon stars. The ...

    • The ionization cone, obscured nucleus, and gaseous outflow in NGC 3281 : a prototypical Seyfert 2 galaxy? 

      Storchi-Bergmann, Thaisa; Wilson, Andrew S.; Baldwin, Jack A. (1992) [Artigo de periódico]
      We present narrow-band images and long-slit spectroscopy of the central region of the highly inclined Seyfert galaxy NGC 3281. The image of the continuum-subtracted [O III] λ4959 emission line shows a very clear conical ...

    • The missing goliath's slingshot : massive black hole recoil at M83 

      Dottori, Horacio Alberto; Díaz, Rubén Joaquín; Albacete Colombo, Juan Facundo; Mast, Damián (2010) [Artigo de periódico]
      The Fanaroff–Riley II radio source J133658.3−295105, which is also an X-ray source, appears to be projected onto the disk of the barred-spiral galaxy M83 at about 60" from the galaxy’s optical nucleus. J133658.3−295105 and ...

    • The multiphase gas structure and kinematics in the circumnuclear region of NGC 5728 

      Shimizu, Taro; Riffel, Rogério; Müller, Allan Schnorr; Storchi-Bergmann, Thaisa; Veilleux, Sylvain (2019) [Artigo de periódico]
      We report on our combined analysis of HST, VLT/MUSE, VLT/SINFONI, and ALMA observations of the local Seyfert 2 galaxy, NGC 5728 to investigate in detail the feeding and feedback of the active galactic nucleus (AGN). The ...

    • The nuclear near-infrared spectral properties of nearby galaxies 

      Mason, Rachel E.; Rodriguez-Ardila, Alberto; Martins, Lucimara Pires; Riffel, Rogério; Gonzalez Martin, Omaira; Ramos Almeida, Cristina; Dutra, Daniel Ruschel; Ho, Luis C.; Thanjavur, Karun; Flohic, Helene; Alonso-Herrero, Almudena; Lira, Paulina; McDermid, Richard; Riffel, Rogemar André; Schiavon, Ricardo P.; Winge, Claudia; Hoenig, Michael D.; Perlman, Eric (2015) [Artigo de periódico]
      We present spectra of the nuclear regions of 50 nearby (D = 1–92 Mpc, median = 20 Mpc) galaxies of morphological types E to Sm. The spectra, obtained with the Gemini Near-IR Spectrograph on the Gemini North telescope, cover ...

    • The nuclear region of NGC 7469 

      Bonatto, Charles Jose; Pastoriza, Miriani Griselda (1990) [Artigo de periódico]
      We have made spectrophotometric observations of the nuclear and circumnuclear regions of the Seyfert 1 galaxy NGC 7469, and we analyze the dynamics and structure of the emission-line regions. In the nuclear region of NGC ...

    • The nucleus of C16.16 : another case of a double-peaked active galactic nucleus 

      Rodriguez-Ardila, Alberto; Pastoriza, Miriani Griselda; Bica, Eduardo Luiz Damiani; Maza, Jose (1996) [Artigo de periódico]
      We study optical spectra in high and low activity states of the faint, distant Seyfert 1 galaxy C16.16. A strong stellar population contribution to the continuum is observed, even in the high-state spectrum. The low-ionization ...

    • The O [iota] line emission in active galactic nuclei revisited 

      Rodriguez-Ardila, Alberto; Viegas, Sueli Maria Marino; Pastoriza, Miriani Griselda; Prato, Lisa A.; Donzelli, Carlos J. (2002) [Artigo de periódico]
      UV, visible, and near-infrared spectroscopy is used to study the transitions of neutral oxygen leading to the emission of broad O i λ8446, λ11287, and λ1304 in active galactic nuclei. From the strength of the former two ...

    • The role of host galaxy for the environmental dependence of active nuclei in local galaxies 

      Davies, Richard I.; Hicks, Erin K. S.; Erwin, Peter; Burtscher, Leonard; Contursi, Alessandra; Genzel, Reinhard; Janssen, Annemieke; Koss, Michael; Lin, Ming-Yi; Lutz, Dieter; Maciejewski, Witold B.; Muller-Sanchez, Francisco; Orban de Xivry, Gilles; Ricci, Claudio; Riffel, Rogério; Riffel, Rogemar André; Rosario, David; Schartmann, Marc; Müller, Allan Schnorr; Shimizu, Taro; Sternberg, Amiel; Sturm, Eckhard; Storchi-Bergmann, Thaisa; Tacconi, Linda J.; Veilleux, Sylvain (2017) [Artigo de periódico]
      We discuss the environment of local hard X-ray selected active galaxies, with reference to two independent group catalogues. We find that the fraction of these AGN in S0 host galaxies decreases strongly as a function of ...

    • The spatial extension of extended narrow line regions in MaNGA AGN 

      Chen, Jianhang; Shi, Yong; Dempsey, Ross; Law, David R.; Chen, Yanmei; Yan, Renbin; Bing, Longji; Rembold, Sandro Barboza; Li, Songlin; Yu, Xiaoling; Riffel, Rogemar André; Brownstein, Joel R.; Riffel, Rogério (2019) [Artigo de periódico]
      In this work, we revisit the size–luminosity relation of the extended narrow line regions (ENLRs) using a large sample of nearby active galactic nuclei (AGNs) from the Mapping Nearby Galaxies at Apache Point Observatory ...

    • The stellar content of active galaxies 

      Fernandes Junior, Roberto Cid; Storchi-Bergmann, Thaisa; Schmitt, Henrique Roberto (1998) [Artigo de periódico]
      We present the results of a long-slit spectroscopic study of 38 active and four normal galaxies. Stellar absorption features, continuum colours and their radial variations are analysed in an effort to characterize the ...

    • The stellar populations of low-luminosity active galactic nuclei. I. Ground-based observations 

      Fernandes, Roberto Cid; González Delgado, Rosa M.; Schmitt, Henrique Roberto; Storchi-Bergmann, Thaisa; Martins, Lucimara Pires; Pérez Jiménez, Enrique; Heckman, Timothy M.; Leitherer, Claus; Schaerer, Daniel (2004) [Artigo de periódico]
      We present a spectroscopic study of the stellar populations of low-luminosity active galactic nuclei (LLAGNs). Our main goal is to determine whether the stars that live in the innermost (100 pc scale) regions of these ...

    • The stellar populations of low-luminosity active galactic nuclei – III. Spatially resolved spectral properties 

      Fernandes Junior, Roberto Cid; González Delgado, Rosa M.; Storchi-Bergmann, Thaisa; Martins, Lucimara Pires; Schmitt, Henrique Roberto (2005) [Artigo de periódico]
      In a recently completed survey of the stellar population properties of low-ionization nuclear emission-line regions (LINERs) and LINER/H II transition objects (TOs), we have identified a numerous class of galactic nuclei ...

    • The stellar populations of low-luminosity active galactic nuclei. II. Space telescope imaging spectrograph observations 

      González Delgado, Rosa M.; Fernandes, Roberto Cid; Storchi-Bergmann, Thaisa; Martins, Lucimara Pires; Pérez Jiménez, Enrique; Heckman, Timothy M.; Leitherer, Claus; Schaerer, Daniel (2004) [Artigo de periódico]
      We present a study of the stellar populations of low-luminosity active galactic nuclei (LLAGNs). Our goal is to search for spectroscopic signatures of young and intermediate-age stars and to investigate their relationship ...