Chemical Abundances of the Highly Obscured Galactic Globular Clusters 2MASS GC02 and Mercer 5

Abstract

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~50000) in the 15500.0 A - 15575.0 A 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.

arXiv comment31 pages (PASP manuscript style), 5 figures, 6 tables. Accepted for publication in the April 2015 issue of PASP

References in corpus (19)

• The Seventh Data Release of the Sloan Digital Sky Survey
• GLIMPSE: I. A SIRTF Legacy Project to Map the Inner Galaxy
• VISTA Variables in the Via Lactea (VVV): The public ESO near-IR variability survey of the Milky Way
• The effective temperature scale of FGK stars. II. Teff : color : [Fe/H] calibrations
• The Evolution of Isotope Ratios in the Milky Way Galaxy
• Near-IR properties of 24 Globular Clusters in the Galactic Bulge
• Multi-Element Abundance Measurements from Medium-Resolution Spectra. I. The Sculptor Dwarf Spheroidal Galaxy
• Discovery of a Faint Old Stellar System at 150 kpc
• Serendipitous 2MASS Discoveries Near the Galactic Plane: A Spiral Galaxy and Two Globular Clusters
• Variable stars in the VVV globular clusters. I. 2MASS-GC02 and Terzan10
• High resolution near-IR spectra of NGC 6624 and NGC 6569
• Abundances in bulge stars from high-resolution, near-IR spectra I. The CNO elements observed during the science verification of CRIRES at VLT
• Near-Infrared photometry of four metal-rich Bulge globular clusters: NGC6304, NGC6569, NGC6637, NGC6638
• FSR1767 - a new globular cluster in the Galaxy
• An empirical tool to derive metallicity, reddening and distance for old stellar populations from near IR Color Magnitude Diagrams
• FSR584 - a new globular cluster in the Galaxy?
• High-resolution CRIRES spectra of Terzan1: a metal-poor globular cluster toward the inner bulge
• FSR0190 - Another old distant galactic cluster
• Pfleiderer2: identification of a new globular cluster in the Galaxy

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• Classifying globular clusters and applying them to estimate the mass of the Milky Way
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• Spectroscopic Observations of Obscured Populations in the Inner Galaxy: 2MASS-GC02, Terzan 4, and the 200 km/s stellar peak
• Variable stars in the VVV globular clusters. II. NGC6441, NGC6569, NGC6626 (M28), NGC6656 (M22), 2MASS-GC02, and Terzan10