The metal content of the bulge globular cluster NGC 6528

Author(s)

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

• Document type: Journal article
• Source: Astronomy & Astrophysics; v. 423, p. 507-515, 2004.
• Field of knowledge: Physical Sciences and Mathematics - Astronomy

Abstract

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)

• FAPESP's process: 00/10406-4 - Chemical evolution and stellar populations of the galaxy, magellanic clouds and elliptical galaxies, based on spectroscopy and imaging
• Grantee: Beatriz Leonor Silveira Barbuy
• Support Opportunities: Research Projects - Thematic Grants