Infrared echelle spectroscopy of Palomar 6 and M71

被引:29
作者
Lee, JW
Carney, BW
Balachandran, SC
机构
[1] Sejong Univ, Astrophys Res Ctr Struct & Evolut Cosmos, Dept Astron & Space Sci, Seoul 143747, South Korea
[2] Univ N Carolina, Dept Phys & Astron, Chapel Hill, NC 27599 USA
[3] Univ Maryland, Dept Astron, College Pk, MD 20742 USA
关键词
Galaxy : bulge; globular clusters : individual (Palomar 6; M71); infrared : stars; stars : abundances;
D O I
10.1086/425047
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We present high-resolution infrared echelle spectroscopy for the globular clusters Palomar 6 and M71. Our mean heliocentric radial velocity of Pal 6 is +180.6 +/- 3.2 km s(-1) and is 20 km s(-1) lower than that found by Minniti in 1995. Contrary to the previous metallicity estimates using low-resolution spectroscopy, our results show that Pal 6 has an intermediate metallicity, with [Fe/H] = -1.0 +/- 0.1, and is slightly more metal poor than M71. Reasonable changes in the surface temperature or the microturbulent velocity of the model atmospheres do not affect [Fe/H] at more than +/-0.2 dex. In spite of its high metallicity, on the basis of the spectrum of a single cluster member the [Si/Fe] and [Ti/Fe] ratios of Pal 6 appear to be enhanced by 0.4 and 0.5 dex, respectively, suggesting that the Galactic inner halo may have experienced a very rapid chemical enrichment history.
引用
收藏
页码:2388 / 2401
页数:14
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