The metallicity of K giant stars along the Sagittarius streams

• 来源期刊: 天文和天体物理学研究
• 年，卷（期）: 2017,（7）
• 页码范围: 121-128
• 页数: 8页
• 语种: 英文
• DOI: 10.1088/1674-4527/17/7/76

摘要

The Large Sky-Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) Data Release 3 provided 341 691 K giant stars with stellar parameters.Based on the models of Law & Majewski,we identified 252 K giant stars in the leading stream associated with the Sagittarius (Sgr) dwarf galaxy.We obtained 132 K giant stars belonging to the trailing arm of Sgr using the model of Belokurov et al.We studied the metallicity distribution of member stars along the streams and found a flat gradient in the first wrap of the leading stream,-(0.88±0.3) × 10-3 dex/(°) in the second wrap of the leading stream and -(1.2±0.3) × 10-3 dex/(°) in the first wrap of the trailing stream.Moreover,we obtained a combined metallicity gradient with our sample and data from the literature.We also analyzed the properties of an overdensity,which is located in the leading stream of the Sgr.