Decoding the morphological evolution of open clusters

doi:10.1051/0004-6361/202141460

	Decoding the morphological evolution of open clusters
	Hu, Qingshun 1,2; Zhang, Yu 1,2; Esamdin, Ali 1,2
刊名	ASTRONOMY & ASTROPHYSICS
	2021-12-02
卷号	656 页码:11
关键词	Galaxy: stellar content methods: statistical open clusters and associations: general
ISSN号	0004-6361
DOI	10.1051/0004-6361/202141460
通讯作者	Zhang, Yu(zhy@xao.ac.cn)
英文摘要	Context. The properties of open clusters such as metallicity, age, and morphology are useful tools in studies of the dynamic evolution of open clusters. The morphology of open clusters can help us better understand the evolution of such structures. Aims. We aim to analyze the morphological evolution of 1256 open clusters by combining the shapes of the sample clusters in the proper motion space with their morphology in the two-dimensional spherical Galactic coordinate system, providing their shape parameters based on a member catalog derived from Gaia Second Data Release as well as data from the literature. Methods. We applied a combination of a nonparametric bivariate density estimation with the least square ellipse fitting to derive the shape parameters of the sample clusters. Results. We derived the shape parameters of the sample clusters in the two-dimensional spherical Galactic coordinate system and that of the proper motion space. By analyzing the dislocation of the sample clusters, we find that the dislocation, d, is related to the X-axis pointing toward the Galactic center, Y-axis pointing in the direction of Galactic rotation, and the Z-axis (log(vertical bar H vertical bar/pc)) that is positive toward the Galactic north pole. This finding underlines the important role of the dislocation of clusters in tracking the external environment of the Milky Way. The orientation (q(pm)) of the clusters, with e(pm) >= 0.4, presents an aggregate distribution in the range of -45 degrees to 45 degrees, comprising about 74% of them. This probably suggests that these clusters tend to deform heavily in the direction of the Galactic plane. NGC 752 is in a slight stage of expansion in the two-dimensional space and will become deformed, in terms of its morphology, along the direction perpendicular to the original stretching direction in the future if no other events occur. The relative degree of deformation of the sample clusters in the short-axis direction decreases as their ages increase. On average, the severely distorted sample clusters in each group account for about 26% +/- 9%. This possibly implies a uniform external environment in the range of vertical bar H vertical bar <= 300 pc if the sample completeness of each group is not taken into account.
资助项目	National Natural Science Foundation of China[U2031209] ; National Natural Science Foundation of China[U2031204] ; Youth Innovation Promotion Association CAS[2018080] ; 2017 Heaven Lake Hundred-Talent Program of Xinjiang Uygur Autonomous Region of China
WOS关键词	SOLAR NEIGHBORHOOD ; GAIA DR2 ; STARS ; PHOTOMETRY ; ASTROPY ; PYTHON ; DISC
WOS研究方向	Astronomy & Astrophysics
语种	英语
出版者	EDP SCIENCES S A
WOS记录号	WOS:000725148100004
资助机构	National Natural Science Foundation of China ; Youth Innovation Promotion Association CAS ; 2017 Heaven Lake Hundred-Talent Program of Xinjiang Uygur Autonomous Region of China
内容类型	期刊论文
源URL	[http://ir.xao.ac.cn/handle/45760611-7/4407]
专题	新疆天文台_光学天文与技术应用研究室
通讯作者	Zhang, Yu
作者单位	1.Chinese Acad Sci, Xinjiang Astron Observ, Urumqi 830011, Xinjiang, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China
推荐引用方式 GB/T 7714	Hu, Qingshun,Zhang, Yu,Esamdin, Ali. Decoding the morphological evolution of open clusters[J]. ASTRONOMY & ASTROPHYSICS,2021,656:11.
APA	Hu, Qingshun,Zhang, Yu,&Esamdin, Ali.(2021).Decoding the morphological evolution of open clusters.ASTRONOMY & ASTROPHYSICS,656,11.
MLA	Hu, Qingshun,et al."Decoding the morphological evolution of open clusters".ASTRONOMY & ASTROPHYSICS 656(2021):11.