Bibcode
DOI
Peñaloza, F.; Pessev, P.; Vaśquez, Sergio; Borissova, Jura; Kurtev, Radostin; Zoccali, Manuela
Bibliographical reference
Publications of the Astronomical Society of the Pacific, Volume 127, issue 950, pp.329-339
Advertised on:
4
2015
Citations
8
Refereed citations
8
Description
We present the first high spectral resolution abundance analysis of two
newly discovered Galactic globular clusters, namely, Mercer 5 and 2MASS
GC02, residing in regions of high interstellar reddening in the
direction of the Galactic center. The data were acquired with the
Phoenix high-resolution near-infrared echelle spectrograph at Gemini
South (R ˜ 50,000) in the 15,500.0-15,575.0 spectral region. Iron,
oxygen, silicon, titanium, and nickel abundances were derived for two
red giant stars, in each cluster, by comparing the entire observed
spectrum with a grid of synthetic spectra generated with MOOG. We found
[Fe/H] values of -0.86 ± 0.12 and -1.08 ± 0.13 for Mercer
5 and 2MASS GC02, respectively. The [O/Fe], [Si/Fe], and [Ti/Fe] ratios
of the measured stars of Mercer 5 follow the general trend of both bulge
field and cluster stars at this metallicity, and are enhanced by
≥+0.3. The 2MASS GC02 stars have relatively lower ratios, but still
compatible with other bulge clusters. Based on metallicity and abundance
patterns of both objects, we conclude that these are typical bulge
globular clusters.