Kinematic evidence for an old stellar halo in the Large Magellanic Cloud

被引：61

作者：

Minniti, D

Borissova, J

Rejkuba, M

Alves, DR

Cook, KH

Freeman, KC

机构：

[1] Pontificia Univ Catolica Chile, Dept Astron, Santiago 22, Chile

[2] European So Observ, D-85748 Garching, Germany

[3] Columbia Univ, Astrophys Lab, New York, NY 10027 USA

[4] Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA

[5] Australian Natl Univ, Mt Stromlo Observ, Res Sch Astron & Astrophys, Canberra, ACT, Australia

来源：

SCIENCE | 2003年 / 301卷 / 5639期

关键词：

D O I：

10.1126/science.1088529

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

The oldest and most metal-poor Milky Way stars form a kinematically hot halo, which motivates the two major formation scenarios for our galaxy: extended hierarchical accretion and rapid collapse. RR Lyrae stars are excellent tracers of old and metal-poor populations. We measured the kinematics of 43 RR Lyrae stars in the inner regions of the nearby Large Magellanic Cloud (LMC) galaxy. The velocity dispersion equals 53 +/- 10 kilometers per second, which indicates that a kinematically hot metal-poor old halo also exists in the LMC. This result suggests that our galaxy and smaller late-type galaxies such as the LMC have similar early formation histories.

引用

页码：1508 / 1510

页数：3

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