The relations between the metallicity and orbital parameters of Galactic disk stars

作     者：LI Ji SUN JianAn FU RuiJuan 

作者机构：College of Physics Science&Information EngineeringHebei Normal UniversityShijiazhuang 050016China 

出 版 物：《Science China(Physics,Mechanics & Astronomy)》 (中国科学:物理学、力学、天文学(英文版))

年 卷 期：2010年第53卷第7期

页      面：1348-1356页

核心收录：

学科分类：07[理学] 070401[理学-天体物理] 0704[理学-天文学] 

基　　金：supported by the National Natural Science Foundation of China (Grant Nos. 10778616 and 10673002) 

主　　题：Galaxy Galactic disk star orbital eccentricity abundance gradient 

摘      要：The iron abundance gradient in the Galactic disk provides fundamental constraints on the chemical evolution of this important component of the ***,there are still some arguments about the shape of the iron abundance gradient across the Galactic stellar *** provide quantitative constraints on these trends,we constructed an unbiased stellar sample from the common objects of two large *** sample consists of 4004 disk stars in the solar neighborhood with the range of metallicity [Fe/H] from ^-1.0 to ~0.5,including 3855 thin disk stars and 146 thick disk *** range of their mean Galactocentric distances R m is from ~4 to ~11 kpc,and the range of their maximum vertical distance from the Galactic Plane Z max is from 0 to ~3.5 *** relations of the stellar metallicity [Fe/H] with the orbital eccentricity e,and [Fe/H] with R m,as well as [Fe/H] with Z max are investigated in *** results showed that:(1) The orbital eccentricity of disk stars decreases with increasing metallicity,while this trend becomes flat for stars with [Fe/H]-0.2.(2) For thin disk,there is a clear radial iron gradient of-0.051±0.005 dex/***,this metallicity gradient is discontinuous once we split the sample into the inner(Rm8kpc) and outer disk(Rm≥8 kpc):a slope of about 0 dex/kpc is present in the inner disk and a slope of-0.12 dex/kpc is in the outer *** the thick disk,there is no trend of [Fe/H] with R m.(3) The vertical gradient of iron abundance is-0.146 dex/kpc and-0.251 dex/kpc for the thick and thin disks,***,the vertical abundance gradient shows a steeper trend with the evolution of the *** results confirm the collapse mechanism associated with the formation and evolution of the Galactic disk.