木星平运动共振和Ⅰ型迁移对土星核形成的作用  

On the formation of Saturn's core:the effect of mean-motion resonances with Jupiter and type I migration of embryos

作　　者：吴晓梅[1,2] 周济林[2] 张辉[2] 宫衍香[1,2] 

机构地区：[1]泰山学院物理与电子工程学院,泰安271021 [2]南京大学天文与空间科学学院,南京210093

出　　处：《中国科学：物理学、力学、天文学》2014年第1期100-108,共9页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家自然科学基金(批准号:10925313,11003010);山东省自然科学基金(编号:ZR2010AM024,ZR2010AQ023);山东省高等学校青年骨干教师国内访问学者项目经费资助

摘　　要：采用三维N体模拟研究了在太阳星云盘中木星完全形成后土星核的快速形成.除了考虑太阳,木星及行星胚胎间的引力相互作用,还考虑了使行星胚胎发生Ⅰ型迁移和轨道圆化效应的气体盘潮汐作用.模拟表明:木星的平运动共振构型和行星Ⅰ型迁移大大地提高了行星胚胎的碰撞吸积率,同时木星的引力摄动有效地阻止大行星胚胎过快向内迁移而落入太阳中,最终在两百万年的时间内有可能在雪线之外靠近木星3:2平运动共振处吸积形成一颗土星核.The rapid formation of Saturn＇s core after the assembly of Jupiter in the solar nebula is studied using three-dimensional N-body simulations. Mutual gravitational interaction among the Sun, Jupiter and embryos are considered. We also take into account type I migration, orbital eccentricity and inclination damping of the embryos due to tidal interaction with a gas disk. Numerical simulations show that the mean-motion resonances with Jupiter and type I migration of embryos greatly increase the collisional accretion rate between them, while gravitational perturbations of Jupiter prevent bigger embryos from rapidly migrating to the Sun. Ultimately, an embryo like the Saturn＇s core can form at a position that is always closely in 3：2 mean-motion resonances with Jupiter （outside the snow line） in two million years.

关 键 词：数值模拟 土星核 平运动共振 I型迁移 

分 类 号：P185[天文地球—天文学]