On the Importance of Gas Flow through Porous Bodies for the Formation of Planetesimals
On the Importance of Gas Flow through Porous Bodies for the Formation of Planetesimals
复制标题
论气体流动通过多孔体对于星子形成的重要性
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
O. Krauss
中科院分区：
文献类型：
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作者：
G. Wurm;G. Paraskov;O. Krauss
原行星盘中的微行星和它们的前身是非常多孔的。因此，围绕这些物体的气流将伴随着通过它们的气流。我们计算了这种气流将如何影响一个小物体对一个大于1米的物体的影响。在具有高孔隙率的大物体（靶）的前侧上，存在边界层，其特征在于朝向表面的气流。我们发现，在典型的条件下，在原行星盘碰撞，碰撞的碎片将留在这个边界层内。这些碎片将通过气体阻力返回目标。在这些二次碰撞中，较大的天体将净增长。该机制适用于所有大小，直到行星大小。这支持了小行星（更大的天体）是由更小的天体碰撞形成的观点。
Planetesimals and their precursors in protoplanetary disks are very porous. Thus, a gas flow around such bodies will be accompanied by gas flow through them. We calculate how this gas flow will influence the impact of a small body on a body larger than 1 m in size. On the front side of a large body (target) with high porosity there is a boundary layer that is characterized by a gas flow toward the surface. We find that under typical conditions with respect to collisions in protoplanetary disks, fragments of a collision will stay inside this boundary layer. These fragments will return to the target by gas drag. Net growth of the larger body in these secondary collisions will occur. The mechanism works for all sizes up to planetesimal size. This supports the idea that planetesimals (kilometer-sized bodies) build up from collisions of smaller bodies.
影响因子：
3.2
作者：
V. Mannings;A. Boss;S. Russell
通讯作者：
V. Mannings;A. Boss;S. Russell