Nitrogen abundances in giant stars of the globular cluster NGC 6752

被引：119

作者：

Yong, David ^{[1
]}

Grundahl, Frank ^{[2
]}

Johnson, Jennifer A. ^{[3
]}

Asplund, Martin ^{[4
]}

机构：

[1] Australian Natl Univ, Mt Stromlo Observ, Res Sch Astron & Astrophys, Weston, ACT 2611, Australia

[2] Univ Aarhus, Dept Phys & Astron, DK-8000 Aarhus C, Denmark

[3] Ohio State Univ, Dept Astron, Columbus, OH 43210 USA

[4] Max Planck Inst Astrophys, D-85741 Garching, Germany

来源：

ASTROPHYSICAL JOURNAL | 2008年 / 684卷 / 02期

关键词：

galaxy : abundances; globular clusters : individual (NGC 6752); stars : abundances;

D O I：

10.1086/590658

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We present N abundances for 21 bright giants in the globular cluster NGC 6752 based on high-resolution UVES spectra of the 3360 angstrom NH lines. We confirm that the Stromgren c(1) index traces the N abundance and find that the star-to-star N abundance variation is 1.95 dex, at the sample's luminosity. We find statistically significant correlations, but small-amplitude variations, between the abundances of N and alpha-, Fe-peak, and s-process elements. Analyses using model atmospheres with appropriate N, O, Na, and Al abundances would strengthen, rather than mute, these correlations. If the small variations of heavy elements are real, then the synthesis of the N anomalies must take place in stars which also synthesize alpha-, Fe-peak, and s-process elements. These correlations offer support for contributions from both asymptotic giant branch and massive stars to the globular cluster abundance anomalies.

引用

页码：1159 / 1169

页数：11

共 58 条

[1] The effective temperature scale of giant stars (F0-K5) -: II.: Empirical calibration of Teff versus colours and [Fe/H] [J].