彗木相撞中的惯性引力波  

The Inertia-gravity Waves Caused by the Impact of Shoemaker-Levy9 with Jupiter

作　　者：包纲[1,2] 陈道汉[1,2] 马月华[1,2] 

机构地区：[1]中国科学院紫金山天文台,南京210008 [2]中国科学院国家天文台,北京100012

出　　处：《天文学报》2004年第3期279-287,共9页Acta Astronomica Sinica

基　　金：国家自然科学基金(10273024);小行星基金会资助

摘　　要：苏梅克-列维9号彗星(SL9)与木星相撞后,在木星上观测到的以常速度(-450 m/s)向外扩展的圆环意味着这是碰撞在木星大气中引起的线性波动.我们选取:非旋转、无粘性、密度分层、不可压缩的木星大气模型,而且木星大气以水平速度U=b+az运动;给出初始扰动压力p(r;0)作为碰撞的初始条件,用流体力学方程组求解了彗木相撞中的惯性引力波.结果表明:当木星大气以速度U=U0(-170 m/s)运动时,彗星碎片的大部分能量都用来产生内波,同时还得到彗星碎片的撞击深度H与水平相速vp的关系式.当木星大气以速度为U=b+az运动时,木星大气的扰动能量不再是在动能和势能间均分.After the collision between Comet Shoemaker-Levy 9 (SL9)and Jupiter, some ring structures propagating outwards at constant speed (-450m/s) were observed on the surface of Jupiter, which implicates these rings are linear waves caused by the collision. A linear model of the comet's collision with Jupiter is presented, in which Jovian atmosphere is considered as a non-rotated, inviscid, stratified and incompressive fluid layer which moves at a speed of U = b + az ;We take an initial impulsive pressure p (r; 0) as the initial condition and use fluid dynamics equations to solve the inertia-gravity waves. It is found that most part of the perturbation energy is used to produce the internal waves when Jovian atmosphere moves at constant speed (U = U0(-170m/s)). The relationship between impacting depth H of comet's fragments and horizontal phase speed vp is deduced. Finally, the inertia gravity waves are discussed when U = b + az and it is found that the perturbation energy is not divided equally between kinetic energy and potential energy because of the effect of shear.

关 键 词：彗星 木星 惯性引力波 常速度 线性波动 

分 类 号：P185[天文地球—天文学]