High-resolution infrared spectra of NGC 6342 and 6528: two moderately reddened bulge globular clusters

2004/10/21 by L. Origlia, E. Valenti, R. Michael Rich +1 · 6 citations
Earth and Planetary Sciences · Physics and Astronomy · #Geological and Geochemical Analysis #High-pressure geophysics and materials #Stellar, planetary, and galactic studies #astro-ph

paper · pdf · doi:10.1111/j.1365-2966.2004.08529.x

published as Mon.Not.Roy.Astron.Soc. 356 (2005) 1276-1282 · 8 pages, 5 figures, accepted by MNRAS

arxiv created 2004/10/21 · openalex publication_date 2005/01/13 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28

Abstract

Using the Near Infrared Spectrometer (NIRSPEC) spectrograph at Keck II, we have obtained infrared (IR) echelle spectra covering the range 1.5 –1.8 μm for the moderately reddened bulge globular clusters NGC 6342 and 6528, finding [Fe/H]=−0.60 and −0.17 dex, respectively. We measure an average α-enhancement of ≈+0.33 dex in both clusters, consistent with previous measurements on other metal-rich bulge clusters, and favouring the scenario of a rapid bulge formation and chemical enrichment. We also measure very low 12C/13C isotopic ratios (≈5 in NGC 6342 and ≈8 in NGC 6528), suggesting that extra-mixing mechanisms resulting from cool bottom processing are at work during evolution along the red giant branch (RGB).

Citations

• Red giant branch in near-infrared colour-magnitude diagrams - I. Calibration of photometric indices
• Proton‐Capture Nucleosynthesis in Globular Cluster Red Giant Stars
• ABUNDANCE RATIOS AND GALACTIC CHEMICAL EVOLUTION

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