论文标题
小行星（3200）Phaethon和（155140）2005 UD的动力学演变和热历史
Dynamical Evolution and Thermal History of Asteroids (3200) Phaethon and (155140) 2005 UD
论文作者
论文摘要
近地物（NEOS）（NEOS）（3200）Phaethon和（155140）2005 UD被认为具有共同的起源，前者在Perihelion中表现出尘埃活动，被认为可以直接提供Geminid Meteor流。这两个对象目前都有很小的围围侧距离，从而导致它们的周围温度为或超过1000K。Phaethon的当前活动与靠近太阳的Neos的破坏有关，这很可能在过去产生了与小星产相关的流星流。我们使用热物理模型（TPM）和每个对象的轨道整合的组合对Phaethon和2005 UD的过去热特性进行建模。从模型中提取诸如最高每日温度，最大热梯度和不同深度时温度的温度特征，该温度特征是为预定义的A和E集合的。接下来，使用Phaethon和2005 UD的轨道克隆的动态整合来估计每个对象的过去轨道元素。然后将这些动力学结果与温度特性结合使用，以建模热特性的过去演化，例如最高（和最小）表面温度和热梯度。我们发现矮星（2）帕拉斯不太可能是Phaethon和2005 UD的母体，并且更有可能来源在小行星带的内部。 Phaethon和2005 UD的轨道历史的特征是循环变化，导致围围比值定期在当今值和0.3 au之间转移。我们发现，在这个时间尺度上，地下温度太大，除非积极提供以某种方式提供水冰。近地表热梯度强烈表明热压裂可能非常有效地分解表面岩石石。
The near-Earth objects (NEOs) (3200) Phaethon and (155140) 2005 UD are thought to share a common origin, with the former exhibiting dust activity at perihelion that is thought to directly supply the Geminid meteor stream. Both of these objects currently have very small perihelion distances, which results in them having perihelion temperatures of or exceeding 1000 K. The current activity from Phaethon is relevant to the destruction of NEOs close to the Sun, which most likely has produced meteor streams linked to asteroids in the past. We model the past thermal characteristics of Phaethon and 2005 UD using a combination of a thermophysical model (TPM) and orbital integrations of each object. Temperature characteristics such as maximum daily temperature, maximum thermal gradient, and temperature at varying depths are extracted from the model, which is run for a predefined set of a and e. Next, dynamical integrations of orbital clones of Phaethon and 2005 UD are used to estimate the past orbital elements of each object. These dynamical results are then combined with the temperature characteristics to model the past evolution of thermal characteristics such as maximum (and minimum) surface temperature and thermal gradient. We find that dwarf planet (2) Pallas is unlikely to be the parent body for Phaethon and 2005 UD, and it is more likely that the source is in the inner part of the asteroid belt. The orbital histories of Phaethon and 2005 UD are characterized by cyclic changes in, resulting in perihelia values periodically shifting between present-day values and 0.3 au. We find that the subsurface temperatures are too large over this timescale for water ice to be stable unless actively supplied somehow. The near-surface thermal gradients strongly suggest that thermal fracturing may be very effective at breaking down surface regolith.
