NGC 2419-ANOTHER REMNANT OF ACCRETION BY THE MILKY WAY

被引：65

作者：

Cohen, Judith G. ^{[1
]}

Kirby, Evan N. ^{[1
]}

Simon, Joshua D. ^{[2
]}

Geha, Marla ^{[3
]}

机构：

[1] CALTECH, Palomar Observ, Pasadena, CA 91125 USA

[2] Carnegie Observ, Pasadena, CA 91101 USA

[3] Yale Univ, Dept Astron, New Haven, CT 06520 USA

来源：

ASTROPHYSICAL JOURNAL | 2010年 / 725卷 / 01期

基金：

美国国家科学基金会;

关键词：

Galaxy: formation; Galaxy: halo; globular clusters: individual (NGC 2419); GALACTIC GLOBULAR-CLUSTERS; VELOCITY DISPERSION; GIANT STARS; HALO CLUSTERS; DWARF GALAXY; ACS SURVEY; PALOMAR-13; ABUNDANCES; PHOTOMETRY; NGC-2419;

D O I：

10.1088/0004-637X/725/1/288

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We isolate a sample of 43 upper red giant branch stars in the extreme outer halo Galactic globular cluster (GC) NGC 2419 from two Keck/DEIMOS slitmasks. The probability that there is more than one contaminating halo field star in this sample is extremely low. Analysis of moderate-resolution spectra of these cluster members, as well as of our Keck/HIRES high-resolution spectra of a subsample of them, demonstrates that there is a small but real spread in Ca abundance of similar to 0.2 dex within this massive metal-poor GC. This provides additional support to earlier suggestions that NGC 2419 is the remnant of a dwarf galaxy accreted long ago by the Milky Way.

引用

页码：288 / 295

页数：8

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CONROY C, 2010, APJ IN PRESS

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