Mass segregation in very young open clusters: A case study of NGC 2244 and NGC 6530

	Mass segregation in very young open clusters: A case study of NGC 2244 and NGC 6530
	Chen, L.; De Grijs, R.; Zhao, J. L.
刊名	ASTRONOMICAL JOURNAL
	2007-10-01
卷号	134 期号:4 页码:1368-1379
关键词	astrometry open clusters and associations : general open clusters and associations : individual ( NGC 2244 stellar dynamics NGC 6530)
英文摘要	We derive the proper motions, membership probabilities, and velocity dispersions of stars in the regions of the young (similar to 2 - 4 Myr old) open clusters NGC 2244 ( the central cluster in the Monoceros R2 association) and NGC 6530 ( the dominant cluster in the Sgr OB1 association) from photographic plate material obtained at Shanghai Astronomical Observatory, with time baselines of 34 and 87 yr, respectively. Both clusters show clear evidence of mass segregation, but they do not exhibit any significant velocity- mass ( or, equivalently, velocity- luminosity) dependence. This provides strong support for the suggestion that the observed mass segregation is at least partially due to the way in which star formation has proceeded in these complex star- forming regions ("primordial'' mass segregation). Based on arguments related to the clusters' published initial mass functions, in conjunction with our new measurements of their internal velocity dispersions (similar to 35 and 8 km s(-1) for NGC 2244 and NGC 6530, respectively), we provide strong arguments in favor of the dissolution of NGC 2244 on very short timescales, while we speculate that NGC 6530 may be more stable against the effects of internal two- body relaxation. However, this latter object may well be destroyed by the strong tidal field prevalent at its location in the Galactic plane in the direction of the Galactic center.
学科主题	星系与宇宙学研究中心
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	HUBBLE-SPACE-TELESCOPE ; LARGE-MAGELLANIC-CLOUD ; ROSETTE MOLECULAR CLOUD ; ORION NEBULA CLUSTER ; H-ALPHA PHOTOMETRY ; OPEN STAR-CLUSTERS ; STELLAR CLUSTERS ; NGC 2244 ; GLOBULAR-CLUSTERS ; INTERNAL MOTIONS
收录类别	SCI
语种	英语
WOS记录号	WOS:000249781800006
公开日期	2010-11-08
内容类型	期刊论文
源URL	[http://119.78.226.72//handle/331011/12048]
专题	上海天文台_星系宇宙学重点实验室
作者单位	1.Chinese Acad Sci, Shanghai Astron Observ, Shanghai 200030, Peoples R China 2.Univ Sheffield, Dept Phys & Astron, Sheffield S3 7RH, S Yorkshire, England 3.Chinese Acad Sci, Natl Astron Observ, Beijing 100012, Peoples R China
推荐引用方式 GB/T 7714	Chen, L.,De Grijs, R.,Zhao, J. L.. Mass segregation in very young open clusters: A case study of NGC 2244 and NGC 6530[J]. ASTRONOMICAL JOURNAL,2007,134(4):1368-1379.
APA	Chen, L.,De Grijs, R.,&Zhao, J. L..(2007).Mass segregation in very young open clusters: A case study of NGC 2244 and NGC 6530.ASTRONOMICAL JOURNAL,134(4),1368-1379.
MLA	Chen, L.,et al."Mass segregation in very young open clusters: A case study of NGC 2244 and NGC 6530".ASTRONOMICAL JOURNAL 134.4(2007):1368-1379.