• Ages and metallicities of m31 star clusters 

      Jablonka, Pascale; Alloin, Danielle Marie; Bica, Eduardo Luiz Damiani (1992) [Artigo de periódico]
      We present spectrophotometric data for 7 globular clusters and 2 open clusters in M31. The wide wavelength range available allows one to derive with confidence reddening, metallicity and age. It appears that the foreground ...
    • CCD imaging of NGC 4861 : ionized gas properties and stellar formation 

      Cepa, Jordi; Vilchez, Jose M.; Dottori, Horacio Alberto; Barth, Clarissa Silva (1994) [Artigo de periódico]
      This work undertakes the study of the galaxy NGC 4861, using imaging centered at the strong lines Hα, Hβ, [O III] λ5007 and nearby continua. Integrated, absolute fluxes of 28 H II regions, and the region known as the bright ...
    • Chemical abundance calibrations for the narrow-line region of active galaxies 

      Storchi-Bergmann, Thaisa; Schmitt, Henrique Roberto; Calzetti, Daniela; Kinney, Anne Louise (1998) [Artigo de periódico]
      We investigate two chemical abundance calibrations for the narrow-line region (NLR) of active galaxies in terms of three easily observable optical emission-line ratios, namely, [O III] λλ4959, 5007/Hβ; [N II] λλ6548, ...
    • High-resolution abundance analysis of two individual stars of the bulge globular cluster NCG 6553 

      Barbuy, Beatriz; Renzini, Alvio; Ortolani, Sergio; Bica, Eduardo Luiz Damiani; Guarnieri, M.D. (1999) [Artigo de periódico]
      A detailed abundance analysis of 2 giants of the metal-rich bulge globular cluster NGC6553 was carried out using high resolution échelle spectra obtained at the ESO 3.6m telescope. The temperature calibration of metal-rich ...
    • Mass loss from red giant stars in M67 : is there any evidence for a metallicity dependence? 

      Carraro, Clóvis Carlos; Girardi, Leo Alberto; Bressan, Alessandro; Chiosi, Cesare (1996) [Artigo de periódico]
      Recent claims in the literature, that the rate of mass loss from red giant branch (RGB) stars in old, open clusters like M 67 and NGC 6791, increases with the metallicity above the value holding for Globular Clusters and ...
    • Metallicity distribution of bulge globular clusters in M31 

      Jablonka, Pascale; Bica, Eduardo Luiz Damiani; Bonatto, Charles Jose; Bridges, Terry J.; Langlois, Maud; Carter, Dave (1998) [Artigo de periódico]
      This paper presents 3600—5400 Å integrated spectra of 19 globular clusters (or candidates) projected on the central regions of M31, r ≤ 5.3' ( ≈ 1.2 kpc). We check the cluster nature of these objects, and derive their ages, ...
    • 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 ...
    • NGC 6522 : an intermediate metallicity globular cluster projected on the baade window 

      Barbuy, Beatriz; Ortolani, Sergio; Bica, Eduardo Luiz Damiani (1994) [Artigo de periódico]
      We studied NGC 6522 colour magnitude diagrams using CCD photometry with BV filters. We have carefully estimated the reddening, which is criticai for Baade Window studies, obtaining E(B-V) = 0.55. We derive for this ...
    • Spectrophotometry of globular clusters in NGC 5128 (centaurus a) : determination of their metallicities 

      Bica, Eduardo Luiz Damiani; Jablonka, Pascale; Pelat, D.; Alloin, Danielle Marie (1996) [Artigo de periódico]
      We have carried out spectrophotometry in the range 3600–9700Å of five globular clusters in NGC 5128 for which previous photometric studies suggested a high metal content. We compare the equivalent widths of a set of metallic ...
    • Super metal-rich clusters g158 and g177 in m31 : clues on the inner bulge/disc transition 

      Bica, Eduardo Luiz Damiani; Jablonka, Pascale; Santos Junior, Joao Francisco Coelho dos; Alloin, Danielle Marie; Dottori, Horacio Alberto (1992) [Artigo de periódico]
      The star clusters G 158 and G 177, located at projected distances smaller than 1.5 kpc from the semi-stellar nucleus of M 31, show spectra extreme in absorption-line strengths, comparable to those from the nuclei of giant ...
    • VLT-UVES abundance analysis of four giants in NGC 6553 

      Alves-Brito, Alan; Barbuy, Beatriz; Zoccali, Manuela; Minniti, Dante; Ortolani, Sergio; Hill, Vanessa; Renzini, Alvio; Pasquini, Luca; Bica, Eduardo Luiz Damiani; Rich, Robert Michael; Meléndez, Jorge; Momany, Yazan (2006) [Artigo de periódico]
      Context. Metal-rich globular clusters trace the formation of bulges. Abundance ratios in the metal-rich globular clusters such as NGC 6553 can constrain the formation timescale of the Galactic bulge. Aims. The purpose of ...