Repositório Digital

A- A A+

Integrated spectral properties of 22 small angular diameter galactic open clusters

.

Integrated spectral properties of 22 small angular diameter galactic open clusters

Mostrar registro completo

Estatísticas

Título Integrated spectral properties of 22 small angular diameter galactic open clusters
Autor Ahumada, Andrea Veronica
Claria Olmedo, Juan Jose
Bica, Eduardo Luiz Damiani
Abstract Aims. Flux-calibrated integrated spectra of a sample of 22 Galactic open clusters of small angular diameter are presented. With one exception (ESO429-SC2), all objects have Galactic longitudes in the range 208° < l < 33°. The spectra cover the range ≈3600−6800 Å, with a resolution of ≈14 Å. The properties of the present cluster sample are compared with those of well-studied clusters located in two 90º sectors, centred at l = 257° and l = 347°. The dissolution rate of Galactic open clusters in these two sectors is examined. Methods. Using the equivalent widths of the Balmer lines and comparing line intensities and continuum distribution of the cluster spectra with those of template cluster spectra with known properties, we derive both foreground reddening values and ages. Thus, we provide information independent of that determined through colour–magnitude diagrams. Results. The derived E(B − V) values for the whole sample vary from 0.0 in ESO 445-SC74 to 1.90 in Pismis 24, while the ages range from ∼3 Myr (NGC 6604 and BH 151) to ∼3.5 Gyr (Ruprecht 2). For six clusters (Dolidze 34, ESO 429-SC2, ESO 445-SC74, Ruprecht 2, BH 151 and Hogg 9) the foreground E(B − V) colour excesses and ages are determined for the first time. The results obtained for the remaining clusters show, in general terms, good agreement with previous photometric results. Conclusions. The age and reddening distributions of the present sample match those of known clusters in the two selected Galactic sectors. The present results would favour a major dissolution rate of star clusters in these two sectors. Two new solar-metallicity templates are defined corresponding to the age groups of (4−5) Myr and 30 Myr among those of Piatti et al. (2002, MNRAS, 335, 233). The Piatti et al. templates of 20 Myr and (3−4) Gyr are here redefined.
Contido em Astronomy and astrophysics. Les Ulis. Vol. 473, no. 2 (Oct. 2007), p. 437-444
Assunto Aglomerados abertos e associações
Galaxias
[en] Methods: observational
[en] Open clusters and associations: general
[en] Techniques: spectroscopic
Origem Estrangeiro
Tipo Artigo de periódico
URI http://hdl.handle.net/10183/98993
Arquivos Descrição Formato
000629550.pdf (1.877Mb) Texto completo (inglês) Adobe PDF Visualizar/abrir

Este item está licenciado na Creative Commons License

Este item aparece na(s) seguinte(s) coleção(ões)


Mostrar registro completo

Percorrer



  • O autor é titular dos direitos autorais dos documentos disponíveis neste repositório e é vedada, nos termos da lei, a comercialização de qualquer espécie sem sua autorização prévia.
    Projeto gráfico elaborado pelo Caixola - Clube de Criação Fabico/UFRGS Powered by DSpace software, Version 1.8.1.