The metal content of the bulge globular cluster NGC 6528

Autor(es)

Zoccali, M. ; Barbuy, B. ^[2] ; Hill, V. ; Ortolani, S. ; Renzini, A. ; Bica, E. ; Momany, Y. ; Pasquini, L. ; Minniti, D. ; Rich, R. M.

• Tipo de documento: Artigo Científico
• Fonte: Astronomy & Astrophysics; v. 423, p. 507-515, 2004.
• Área do conhecimento: Ciências Exatas e da Terra - Astronomia
• Assunto(s): Galáxias Estrelas

Resumo

High resolution spectra of five stars in the bulge globular cluster NGC 6528 were obtained at the 8m VLT UT2-Kueyen telescope with the UVES spectrograph. Out of the five stars, two of them showed evidence of binarity. The target stars belong to the horizontal and red giant branch stages, at 4000 < Tefflt; 4800 K. Multiband V, I, J, H, Ks photometry was used to derive initial effective temperatures and gravities. The main purpose of this study is the determination of metallicity and elemental ratios for this template bulge cluster, as a basis for the fundamental calibration of metal-rich populations. The present analysis provides a metallicity [Fe/H] = -0.1±0.2 and the alpha-elements O, Mg and Si, show [alpha/Fe] = +0.1, where as Ca and Ti are around the solar value or below, resulting in an overall metallicity Z = ZO. (AU)

• Processo FAPESP: 00/10406-4 - Evolução química e populações estelares da galáxia, nuvens de Magalhães e galáxias elípticas, através de espectroscopia e imageamento
• Beneficiário: Beatriz Leonor Silveira Barbuy
• Modalidade de apoio: Auxílio à Pesquisa - Temático