High resolution infrared spectra of NGC 6342 and NGC 6528: two moderately reddened Bulge Globular Clusters

Abstract

Using the NIRSPEC spectrograph at Keck II, we have obtained infrared echelle spectra covering the range 1.5-1.8 micron for the moderately reddened bulge globular clusters NGC 6342 and NGC 6528, finding [Fe/H]= -0.60 and -0.17 dex, respectively. We measure an average alpha-enhancement of approx +0.33 dex in both clusters, consistent with previous measurements on other metal rich bulge clusters, and favoring the scenario of a rapid bulge formation and chemical enrichment. We also measure very low 12C/13C isotopic ratios (approx 5 in NGC 6342 and approx 8 in NGC 6528), suggesting that extra-mixing mechanisms due to cool bottom processing are at work during evolution along the Red Giant Branch.

8 pages, 5 figures, accepted by MNRAS

References in corpus (4)

• The Red Giant Branch in the Near-Infrared Colour-Magnitude Diagrams. I: The calibration of photometric indices
• A near-infrared spectroscopic screening of the red giant populations in omega Centauri
• Gemini-Phoenix infrared high-resolution abundance analysis of five giants in the bulge globular cluster NGC 6553
• Carbon Isotopic Abundances in the Red Giants of Omega Centauri (NGC5139)

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