论文标题
原始磁盘中行星的热物理演变
Thermophysical evolution of planetesimals in the Primordial Disk
论文作者
论文摘要
曾经在太阳的15-30 au处的小型冰冷的行星的原始磁盘被早期太阳系中的巨型行星迁移所破坏。因此，原始磁盘成为当今Kuiper带，分散的磁盘和Oort Cloud的物体的来源区域。我介绍了热物理代码“数值冰冷的身体进化模拟器”或nimbus，并使用它在原始磁盘中断之前研究了行星模因的热物理演化。这样的建模是强制性的，以了解从Oort云中动态新彗星的行为，以及来自分散磁盘的半人马和短期彗星的活性，这些磁盘的返回已预处理到太阳附近。我发现，直径为4-200 km的原始磁盘中的身体在0.1-10 MYR的时间尺度上损失了所有CO ICE，具体取决于大小，这是通过原型极性和长寿命的放射性核素加热的组合。因此，CO和其他高管需要挥发性较小的宿主来存储。我认为两个可能的宿主：无定形的水冰和二氧化碳冰。由于原始磁盘的高光度，一些原始磁盘可能具有明显的结晶，CO：CO2分离和最上面几十米的CO2升华。我讨论这可能如何影响动态新彗星中的昏迷比率和遥远的活动。
The Primordial Disk of small icy planetesimals, once located at 15-30 AU from the Sun, was disrupted by giant planet migration in the early Solar System. The Primordial Disk thereby became the source region of objects in the current-day Kuiper Belt, Scattered Disk, and Oort Cloud. I present the thermophysics code "Numerical Icy Minor Body evolUtion Simulator", or NIMBUS, and use it to study the thermophysical evolution of planetesimals in the Primordial Disk prior to its disruption. Such modelling is mandatory in order to understand the behaviour of dynamically new comets from the Oort Cloud, as well as the activity of Centaurs and short-period comets from the Scattered Disk, that return pre-processed to the vicinity of the Sun. I find that bodies in the midst of the Primordial Disk with diameters ranging 4-200 km lost all their CO ice on time-scales of order 0.1-10 Myr depending on size, through a combination of protosolar and long-lived radionuclide heating. CO and other hypervolatiles therefore require a less volatile host for their storage. I consider two possible hosts: amorphous water ice and CO2 ice. Because of the high luminosity of the protosun, some Primordial Disk bodies may have sustained significant crystallisation, CO:CO2 segregation, and CO2 sublimation in the uppermost few tens of meters. I discuss how this may affect coma abundance ratios and distant activity in dynamically new comets.
