论文标题
辐射扭矩的彗星comae中的灰尘和水冰的演变
Evolution of Dust and Water Ice in Cometary Comae by Radiative Torques
论文作者
论文摘要
彗星提供了有关形成太阳系环境的物理和化学特性的独特信息。了解彗星粉尘和冰如何在阳光的作用下进化对于限制核结构和触发彗星活动的机制至关重要。在本文中，我们首先研究了通过辐射扭矩（大鼠）从彗星核中吹出的粉尘晶粒的旋转破坏。我们发现，通过辐射扭矩破坏（RATD）机制可以将复合晶粒迅速破坏成小片段。然后，我们研究大鼠对冰晶的旋转解吸，发现冰晶粒可以从大型中心距离上解吸，超出了$ r _ {\ rm sub}（\ h_ {2}Ø）\ sim 3 \ sim 3 \ au $的水的升华水半径。我们还计算了由于旋转解吸而导致的水蒸气的产量与彗星的地中心度距离。我们的结果可以解释灰尘特性的变化以及经常从彗星comae观察到的小晶粒的存在。最后，我们建议在较大的以heliepentric距离处的旋转破坏和水冰晶粒的解吸可以触发遥远的彗星的活性。
Comets provide unique information about the physical and chemical properties of the environment in which the Solar system was formed. Understanding how cometary dust and ice evolve under the effect of sunlight is essential for constraining nuclear structure and triggering mechanism of comet activity. In this paper, we first study rotational disruption of dust grains lifted by outgassing from comet nuclei by radiative torques (RATs). We find that composite grains could be rapidly disrupted into small fragments by the Radiative Torque Disruption (RATD) mechanism. We then study rotational desorption of ice grains by RATs and find that icy grains could be desorbed from large heliocentric distances, beyond the sublimation radius of water at $R_{\rm sub}(\H_{2}Ø)\sim 3\AU$. We also calculate the production rate of water vapor versus the heliocentric distance of comets due to rotational desorption. Our results could explain the variation of dust properties and the presence of small grains frequently observed from cometary comae. Finally, we suggest that the activity of distant comets could be triggered by rotational disruption of grains and desorption of water ice grains at large heliocentric distances.
