Repositório Digital

A- A A+

The proper motion of the globular cluster NGC 6553 and of bulge stars with the Hubble Space Telescope

.

The proper motion of the globular cluster NGC 6553 and of bulge stars with the Hubble Space Telescope

Mostrar registro completo

Estatísticas

Título The proper motion of the globular cluster NGC 6553 and of bulge stars with the Hubble Space Telescope
Autor Zoccali, Manuela
Renzini, Alvio
Ortolani, Sergio
Bica, Eduardo Luiz Damiani
Barbuy, Beatriz
Abstract WFPC2 images obtained with the Hubble Space Telescope (HST ) 4.16 years apart have allowed us to measure the proper motion of the metal-rich globular cluster NGC 6553 with respect to the background bulge stars. With a space velocity of (II, ,W)=(−3.5, 230, −3) km s-ˡ, NGC 6553 follows the mean rotation of both disk and bulge stars at a galactocentric distance of 2.7 kpc. While the kinematics of the cluster is consistent with either a bulge or a disk membership, the virtual identity of its stellar population with that of the bulge cluster NGC 6528 makes its bulge membership more likely. The astrometric accuracy is high enough for providing a measure of the bulge proper motion dispersion and conÐrming its rotation. A selection of stars based on the proper motions produced an extremely well-deÐned cluster color-magnitude diagram (CMD), essentially free of bulge stars. The improved turno† deÐnition in the decontaminated CMD conÐrms an old age for the cluster (~13 Gyr), indicating that the bulge underwent a rapid chemical enrichment while being built up at in the early universe. An additional interesting feature of the cluster color-magnitude diagram is a signiÐcant number of blue stragglers stars, whose membership in the cluster is Ðrmly established from their proper motions.
Contido em The Astronomical journal. Chicago. Vol. 121, no. 5 (May 2001), p. 2638-2646
Assunto Aglomerados estelares globulares
Galaxia
Movimento estelar
[en] Astrometry
[en] Galaxy: kinematics and dynamics
[en] Globular clusters : individual (NGC 6553)
Origem Estrangeiro
Tipo Artigo de periódico
URI http://hdl.handle.net/10183/108237
Arquivos Descrição Formato
000292179.pdf (2.471Mb) 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.