AI 中文总结
研究行星体碰撞难观测问题，通过极端碎片盘这一间接特征，发现产生尘埃的碰撞天体质量比尘埃大得多，且质量更大的碎片盘需要更大天体碰撞，揭示了与太阳系岩石行星大小相当的行星正在形成。
AI 中文摘要
行星体之间的碰撞对于像地球这样的岩石行星的形成至关重要，但极难观测。因此我们依赖行星撞击的间接特征，如极端碎片盘——其他恒星周围明亮的红外过剩。极端碎片盘被认为是高能碰撞使大量汽化岩石喷出并迅速凝结成毫米或厘米大小尘埃的结果。然而此前尚无明确方法将观测到的尘埃质量与产生它的碰撞联系起来。本文表明所需的碰撞天体质量比观测到的尘埃质量大几个数量级。发现质量更大的极端碎片盘需要成比例更大的碰撞天体。因此，观测到的最大质量极端碎片盘需要火星到地球质量天体的碰撞。极端碎片盘揭示了与我们太阳系岩石行星大小相当的岩石行星正在形成。
英文摘要
Collisions between planetary bodies are essential to the assembly of rocky planets like the Earth, but they are extremely difficult to observe. We therefore rely on indirect signatures of planetary impacts such as extreme debris disks - bright infrared excesses around other stars. Extreme debris disks are thought to be the result of energetic collisions that ejected large amounts of vaporized rock which rapidly condensed into mm- or cm-sized dust. However, previously there has been no clear way to relate the observed mass of dust to the collision that produced it. Here, we show that the colliding bodies required are orders of magnitude more massive than the mass of dust observed. We find that more massive extreme debris disks require proportionally larger colliding bodies. As a consequence, the most massive observed extreme debris disks require collisions of Mars- to Earth-mass bodies. Extreme debris disks thus reveal the ongoing formation of rocky planets comparable in size to the rocky planets of our own solar system.
Comments10 pages, 3 figures, plus appendices. Accepted for publication in ApJL. Animations to accompany figures can be found at http://philipjcarter.com/ImpactVaporEjecta/
