Astronomy and Astrophysics – Astrophysics
Scientific paper
2001-07-12
Astronomy and Astrophysics
Astrophysics
Accepted for publication in A&A
Scientific paper
10.1051/0004-6361:20010976
Low resolution spectra of 23 stars towards the bulge globular clusters NGC 6528 and NGC 6553 are analysed. Radial velocities and atmospheric parameters are derived in order to check their membership in the clusters. Effective temperatures were obtained from photometric data for stars with Teff > 3800 K, whereas for cooler stars, they were derived from equivalent widths of TiO bands. Calibrations of W(TiO) as a function of stellar parameters based on a grid of synthetic spectra are presented. Metallicities were derived from a comparison of the observed spectra to a grid of synthetic spectra. The sample comprises evolutionary stages from the Red Giant Branch to the Horizontal Branch, with parameters in the range 3200 <= Teff <= 5000 K and -0.5 <= log g <= 2.4. The mean metallicities obtained for NGC 6528 and NGC 6553 are [Fe/H] ~ -0.5 and -0.7, in both cases with [Mg/Fe] = +0.3; assuming the same overabundance for the $\alpha$ elements O, Mg, Si, S, Ca and Ti, this gives [Z/Zsolar] = -0.25 and -0.45. Membership verification by means of low resolution spectra is a crucial step in preparing targets for high resolution spectroscopy with 8m class telescopes.
Barbuy Batriz
Bica Eduardo
Coelho Paula
Idiart Thais
Ortolani Sergio
No associations
LandOfFree
Membership of 23 stars towards the bulge globular clusters NGC 6528 and NGC 6553 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Membership of 23 stars towards the bulge globular clusters NGC 6528 and NGC 6553, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Membership of 23 stars towards the bulge globular clusters NGC 6528 and NGC 6553 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-192227