中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
Stellar Rotation and the Extended Main-sequence Turnoff in the Open Cluster NGC 5822

文献类型:期刊论文

作者Sun,Weijia1; Grijs,Richard de2,3; Deng,Licai4,5,6; Albrow,Michael D.7
刊名The Astrophysical Journal
出版日期2019-05-09
卷号876期号:2
ISSN号0004-637X
关键词galaxies: star clusters: general open clusters and associations: individual (NGC 5822) stars: rotation
DOI10.3847/1538-4357/ab16e4
英文摘要Abstract The origin of extended main-sequence turnoffs (eMSTOs) in intermediate-age (1–3 Gyr) clusters is one of the most intriguing questions in current star cluster research. Unlike the split main sequences found in some globular clusters, which are caused by bimodal populations in age and/or chemical abundances, eMSTOs are believed to be due to stellar rotation. We present a spectroscopic survey of MSTO stars in a nearby, intermediate-age (0.9 Gyr), low-mass (~1.7?×?103 M⊙) Galactic open cluster, NGC 5822. We derive a clean sample of member stars based on Gaia proper motions and parallaxes and confirm the existence of an eMSTO. Using medium-resolution (R?~?4000) Southern African Large Telescope spectra, we derive the rotational velocities of 24 member stars (representing 20% completeness around the eMSTO region) and find that the loci of the main-sequence stars in the eMSTO region show a clear correlation with the projected rotational velocities in the sense that fast rotators are located on the red side of the eMSTO and slow rotators are found on the blue side. By comparison with a synthetic cluster model, we show that the stellar rotational velocities and the eMSTO of NGC 5822 can be well reproduced, and we conclude that stellar rotation is the main cause of the eMSTO in NGC 5822.
语种英语
出版者The American Astronomical Society
WOS记录号IOP:0004-637X-876-2-AB16E4
源URL[http://ir.bao.ac.cn/handle/114a11/26208]  
专题中国科学院国家天文台
作者单位1.Kavli Institute for Astronomy & Astrophysics and Department of Astronomy, Peking University, Yi He Yuan Lu 5, Hai Dian District, Beijing 100871, People's Republic of China
2.Department of Physics and Astronomy, Macquarie University, Balaclava Road, Sydney, NSW 2109, Australia
3.International Space Science Institute—Beijing, 1 Nanertiao, Hai Dian District, Beijing 100190, People's Republic of China
4.Key Laboratory for Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012, People's Republic of China
5.School of Astronomy and Space Science, University of the Chinese Academy of Sciences, Huairou 101408, People's Republic of China
6.Department of Astronomy, China West Normal University, Nanchong 637002, People's Republic of China
7.School of Physical and Chemical Sciences, University of Canterbury, Private Bag 4800, Christchurch, New Zealand
推荐引用方式
GB/T 7714
Sun,Weijia,Grijs,Richard de,Deng,Licai,et al. Stellar Rotation and the Extended Main-sequence Turnoff in the Open Cluster NGC 5822[J]. The Astrophysical Journal,2019,876(2).
APA Sun,Weijia,Grijs,Richard de,Deng,Licai,&Albrow,Michael D..(2019).Stellar Rotation and the Extended Main-sequence Turnoff in the Open Cluster NGC 5822.The Astrophysical Journal,876(2).
MLA Sun,Weijia,et al."Stellar Rotation and the Extended Main-sequence Turnoff in the Open Cluster NGC 5822".The Astrophysical Journal 876.2(2019).

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来源:国家天文台

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