Collisional sticking of organic grains in the solar nebula

利用星际有机物质模拟物进行了加热和碰撞实验，以确定星际有机物质在原太阳星云中的分布，并研究有机颗粒的生长。我们发现在2.1-3.0 Au中有星际有机颗粒，在<2.1 Au中有硅酸盐颗粒，在>3.0 Au中有冰粒。我们还发现，在2.2 Au附近蒸发的气体是非常还原的。2.1-3.0 Au中的有机物质具有很强的粘性，毫米级有机颗粒的粘附阈值速度为5 m/s。这表明有机颗粒聚集体的快速凝聚，甚至在湍流吸积盘的早期阶段形成星子。这个区域的星子成为无球粒陨石的母体。相比之下，在3.0 Au的星子的形成<2.1 AU and >发生在被动盘形成时，因为硅酸盐和冰粒不粘。3.0 Au中的星子<2.1 AU and >分别成为普通和碳质球粒陨石的母体。在这些框架中，我们讨论了陨石的氧化还原状态，陨石和行星的氧同位素组成，以及球粒的形成。我们已经成功地解释了各种序列之间的陨石和行星的日心距离：从太阳的顺序是地球，火星，LL，L，H，E，Aubrite，HED，Acapulcoite，Ureilite，CO，CV，CM，CI。

Heating and collision experiments were performed involving interstellar organic material analogue to determine the distribution of interstellar organic material in the proto solar nebula and to investigate the growth of organic grains. We found that there were interstellar organic grains in 2.1-3.0 AU, silicate grains <2.1 AU, and ice grains>3.0 AU. We also found that gas evaporated at around 2.2 AU is very reductive. The organic material in 2.1-3.0 AU is very sticky ; the sticking threshold velocity of the mm-size organic grains is 5 m/s. This shows a very rapid coagulation of organic grain aggregates, the formation of planetesimals even the early stage of the turbulent accretion disk. The planetesimals in this region become achondrites' parent bodies. In contrast, the formation of planetesimals in <2.1 AU and >3.0 AU occur when passive disk is formed, because silicate and ice grains are not sticky. The planetesimals in <2.1 AU and >3.0 AU become ordinary and carbonaceous chondrites' parent bodies, respectively. In these framework, we discuss a redox state of chondrites, an oxygen isotope composition of meteorites and planets, and the formation of chondrules. We have succeded to give an explanation for various sequences among meteorites and planets by the heliocentric distance only : the sequence from the sun is the Earth, Mars, LL, L, H, E, Aubrite, HED, Acapulcoite, Ureilite, CO, CV, CM, CI.