Photophoretic motion of chondrules, CAIs and large bodies in the Solar Nebula

点击翻译按钮获取中文摘要

Photophoretic particle transport in protoplanetary disks or, more specific, in the solar nebula acts in optical thin parts as the surface or at the inner disk edge. Here, it can outnumber stellar gravity or the gravity of the disk. During the last periods of the project the strength of the photophoretic force on chondrules and other particles could be determined to high accuracy. Part of this was a systematic study starting from determining the 3d composition by tomography over calculating the heat transfer in illuminated particles to real experimental measurements of photophoretic forces on the same particles under microgravity of a drop tower. For the first time this provided equations which are accurate enough to treat sorting and concentration of particles through photophoretic transport. One main goal of the project is to develop such transport models. They will be used to study how particles of different size and composition are sorted or concentrated in different regions of the edge. This study will be extended to larger bodies as well. Overall, this will allow to study the distribution of matter from dust size to km-planetesimals in the early solar system and estimate the importance of photophoresis in this.