论文标题
分子氢冰的破坏及其对1I/2017 U1的影响（`oumuamua）
Destruction of molecular hydrogen ice and Implications for 1I/2017 U1 (`Oumuamua)
论文作者
论文摘要
在我们的太阳系1i/2017 U1（`oumuamua）中观察到的第一个星际物体表现出许多特性的特性，包括极端伸长和加速过剩。最近，\ cite {seligman：2020vb}提出该物体是由分子氢（H $ _ {2} $）冰制成的。问题是H $ _2 $对象是否可以幸免于从出生地点到太阳系的旅行。在这里，我们通过从巨型分子云（GMC）到星际介质（ISM）和太阳系，研究了冰冷的H $ _2 $对象的破坏过程，这是由于星际辐射，气体和尘埃以及宇宙射线。我们发现，由于星光加热而导致的热升华可以破坏少数不到10 Myr的Oumuamua大小的物体。在GMC中进行碰撞加热的热升华可能会破坏h $ _2 $ o o o o o o o o o o oumuamua size的对象，然后它们逃到ISM中。最重要的是，富含h $ _2 $的冰冷谷物的形成不太可能在密集的环境中发生，因为碰撞加热会升高冰冷谷物的温度，因此热升华在谷物生长前迅速摧毁了H $ _2 $增量。
The first interstellar object observed in our solar system, 1I/2017 U1 (`Oumuamua), exhibited a number of peculiar properties, including extreme elongation and acceleration excess. Recently, \cite{Seligman:2020vb} proposed that the object was made out of molecular hydrogen (H$_{2}$) ice. The question is whether H$_2$ objects could survive their travel from the birth sites to the solar system. Here we study destruction processes of icy H$_2$ objects through their journey from giant molecular clouds (GMCs) to the interstellar medium (ISM) and the solar system, owing to interstellar radiation, gas and dust, and cosmic rays. We find that thermal sublimation due to heating by starlight can destroy `Oumuamua-size objects in less than 10 Myr. Thermal sublimation by collisional heating in GMCs could destroy H$_2$ objects of `Oumuamua-size before their escape into the ISM. Most importantly, the formation of icy grains rich in H$_2$ is unlikely to occur in dense environments because collisional heating raises the temperature of the icy grains, so that thermal sublimation rapidly destroys the H$_2$ mantle before grain growth.
