Are Pebble Pile Planetesimals Doomed?
Are Pebble Pile Planetesimals Doomed?
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DOI：
10.1093/mnras/stz107
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发表时间：
2019-01
影响因子：
4.8
通讯作者：
T. Demirci;M. Kruss;J. Teiser;T. Bogdan;F. Jungmann;N. Schneider;G. Wurm
中科院分区：
文献类型：
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作者：
T. Demirci;M. Kruss;J. Teiser;T. Bogdan;F. Jungmann;N. Schneider;G. Wurm
在抛物线飞行实验中，我们研究了低重力、低环境压力下球形玻璃微珠组成的颗粒床的风蚀问题。不同的G水平是由离心力设定的。将现有的参数集扩展到$p=30 0-12 0 0，$pa和g水平$g=1.1-2.2，\rm m，S^-2}$侵蚀阈值仍然与邵和鲁(2 0 0 0年)现有的行星表面风蚀模型一致。从技术上讲，这些参数是实验可以达到的最低值。在原行星盘中存在小行星的情况下，这些实验将侵蚀阈值的必要外推范围从已证实的值减少到目前仍未知的值。我们将我们的结果应用于行星体的稳定性。在原行星盘的内部区域，低于一定大小的鹅卵石堆积的行星体不稳定，会被逆风吹散。
In parabolic flight experiments we studied the wind induced erosion of granular beds composed of spherical glass beads at low gravity and low ambient pressure. Varying g-levels were set by centrifugal forces. Expanding existing parameter sets to a pressure range between $p=300-1200\,$Pa and to g-levels of $g=1.1-2.2\,\rm m\,s^{-2}$ erosion thresholds are still consistent with the existing model for wind erosion on planetary surfaces by Shao & Lu (2000). These parameters were the lowest values that could technically be reached by the experiment. The experiments decrease the necessary range of extrapolation of erosion thresholds from verified to currently still unknown values at the conditions of planetesimals in protoplanetary discs. We apply our results to the stability of planetesimals. In inner regions of protoplanetary discs, pebble pile planetesimals below a certain size are not stable but will be disassembled by a head wind.