Navegação Ciências Exatas e da Terra por Assunto "Globular clusters: general"

Resultados 21-30 de 30

    • New SX Phe variables in the globular cluster NGC 288 

      Martinazzi, Elizandra; Kepler, Souza Oliveira; Costa, Jose Eduardo da Silveira; Pieres, Adriano; Bonatto, Charles Jose; Bica, Eduardo Luiz Damiani; Fraga, Luciano (2015) [Artigo de periódico]
      We report the discovery of two new variable stars in the metal-poor globular cluster NGC 288, found by means of time series CCD photometry. We classified the new variables as SX Phoenicis (SX Phe) due to their characteristic ...

    • NGC 6558 : a blue horizontal branch moderately metal-poor globular cluster in the bulge 

      Barbuy, Beatriz; Zoccali, Manuela; Ortolani, Sergio; Minniti, Dante; Hill, Vanessa; Renzini, Alvio; Bica, Eduardo Luiz Damiani; Gómez, Ana (2007) [Artigo de periódico]
      We present, for the first time, a detailed abundance analysis of five giant stars in the moderately metal-poor bulge globular cluster NGC 6558. Spectra have been obtained at the VLT with the multifiber spectrograph FLAMES ...

    • Optical-near-IR analysis of globular clusters in the IKN dwarf spheroidal : a complex star formation history 

      Tudorica, Alexandru; Georgiev, Iskren Y.; Chies-Santos, Ana Leonor (2015) [Artigo de periódico]
      Context. Age, metallicity, and spatial distribution of globular clusters (GCs) provide a powerful tool for reconstructing major starformation episodes in galaxies. IKN is a faint dwarf spheroidal (dSph) in the M 81 group ...

    • Photometric and structural properties of NGC 6544 : a combined VVV-Hubble Space Telescope study 

      Cohen, Roger; Mauro, Francesco; Geisler, Doug; Moni Bidin, Christian; Dotter, Aaron Loveren; Bonatto, Charles Jose (2014) [Artigo de periódico]
      We combine archival Hubble Space Telescope imaging with wide-field near-infrared photometry to study the neglected metal-poor Galactic globular cluster NGC 6544. A high spatial resolution map of differential reddening over ...

    • The globular cluster NGC 6642 : evidence for a depleted mass function in a very old cluster 

      Balbinot, Eduardo; Santiago, Basilio Xavier; Bica, Eduardo Luiz Damiani; Bonatto, Charles Jose (2009) [Artigo de periódico]
      We present photometry for the globular cluster NGC6642 using the F606W and F814W filters with the Advanced Camera for Surveys in the Wide Field Channel (ACS/WFC) third generation camera on board of Hubble Space Telescope. ...

    • The globular cluster system of the Coma cD galaxy NGC 4874 from Hubble Space Telescope ACS and WFC3/IR imaging 

      Cho, Hyejeon; Blakeslee, John P.; Chies-Santos, Ana Leonor; Jee, Myungkook James; Jensen, Joseph B.; Peng, Eric W.; Lee, Young-Wook (2016) [Artigo de periódico]
      We present new Hubble Space Telescope (HST) optical and near-infrared (NIR) photometry of the rich globular cluster (GC) system NGC 4874, the cD galaxy in the core of the Coma cluster (Abell 1656). NGC 4874 was observed ...

    • The overlooked potential of generalized linear models in astronomy – III. Bayesian negative binomial regression and globular cluster populations 

      Souza, Rafael da Silva de; Hilbe, Joseph; Buelens, Bart; Riggs, J. D.; Cameron, Ewan; Ishida, Emille Eugenia de Oliveira; Chies-Santos, Ana Leonor; Killedar, Madhura (2015) [Artigo de periódico]
      In this paper, the third in a series illustrating the power of generalized linear models (GLMs) for the astronomical community, we elucidate the potential of the class of GLMs which handles count data. The size of a galaxy’s ...

    • The tidal tails of NGC 2298 

      Balbinot, Eduardo; Santiago, Basilio Xavier; Costa, Luiz N. da; Makler, Martín; Maia, Marcio Antonio Geimba (2011) [Artigo de periódico]
      We present an implementation of the matched-filter technique to detect tidal tails of globular clusters. The method was tested using the Sloan Digital Sky Survey (SDSS) data for the globular cluster Palomar 5 revealing its ...

    • Two reddened globular cluster projected close to the galactic center : Palomar 6 and Djorgovski 1 

      Ortolani, Sergio; Bica, Eduardo Luiz Damiani; Barbuy, Beatriz (1995) [Artigo de periódico]
      We present NTT V,I observations of Palomar 6 and Djorgovski 1, two obscured loose clusters in crowded fields. We derive a reddening of E(B - V) = 1.33 ± 0.10, a distance dʘ ≈ 8.9 kpc, and a metallicity of [Fe/H] ≈ -0.4 for ...

    • VLT-UVES analysis of 5 giants in 47 Tucanae 

      Alves-Brito, Alan; Barbuy, Beatriz; Ortolani, Sergio; Momany, Yazan; Hill, Vanessa; Zoccali, Manuela; Renzini, Alvio; Minniti, Dante; Pasquini, Luca; Bica, Eduardo Luiz Damiani; Rich, Robert Michael (2005) [Artigo de periódico]
      High resolution spectra of 5 giants, including a horizontal branch star, of the metal-rich globular cluster 47 Tucanae were obtained with the UVES spectrograph at the 8m VLT UT2-Kueyen telescope. The atmospheric parameters ...