论文标题
原始碟片中的纳米钻石：边缘的生命
Nano-diamonds in proto-planetary discs: Life on the edge
论文作者
论文摘要
在发射中观察到的几种来源中，纳米钻石仍然是灰尘的有趣组成部分。这项工作的重点是在情节盘中观察到的纳米钻石，并试图使用最近衍生的一组光学常数来获取有关其可能的大小，组成和进化的关键信息。使用纳米二叉戟及其光学特性（效率因子QEXT，QSCA，QABS和QPR）的复杂指标用于确定其温度，寿命和漂移速度与半径（0.5-100 nm）的函数（0.5-100 nm），组成（表面氢化状态和受发射状态）和距离距离中的距离。确定恒星HR 4049，Elias 1和HD 97048的纳米钻石温度曲线，在光学上薄的极限。结果表明，大型纳米辅助（A = 30-100 nm）是内盘区域（〜10-50 au）中最热的，因此是最不耐药性的，而在这些区域中，小（<10 nm）完全填充的纳米二号符仍然显着凉爽。我们将在二角盘中的纳米钻石形成的背景下讨论这些结果。大型纳米钻石是最热门的，受到恒星辐射场的影响，但是，辐射压力的影响似乎不足以使它们摆脱危害的方式。然后，在原始星际盘的内部区域中，最能生存并闪耀的纳米钻石似乎很小（A <10 nm），氢化并接近近距离的纳米钻石（〜1.4 nm）。然而，似乎尚无可能在此类地区与他们看似短的寿命调和他们的存在。
Nano-diamonds remain an intriguing component of the dust in the few sources where they have been observed in emission. This work focusses on the nano-diamonds observed in circumstellar discs and is an attempt to derive critical information about their possible sizes, compositions, and evolution using a recently-derived set of optical constants. The complex indices of refraction of nano-diamonds and their optical properties (the efficiency factors Qext, Qsca, Qabs, and Qpr) were used to determine their temperatures, lifetimes, and drift velocities as a function of their radii (0.5-100 nm), composition (surface hydrogenation and irradiated states), and distance from the central stars in circumstellar regions. The nano-diamond temperature profiles were determined for the stars HR 4049, Elias 1, and HD 97048 in the optically-thin limit. The results indicate that large nano-diamonds (a = 30 - 100 nm) are the hottest and therefore the least resistant in the inner disc regions (~ 10-50 AU), while small (a < 10 nm) fully-hydrogenated nano-diamonds remain significantly cooler in these same regions. We discuss these results within the context of nano-diamond formation in circumstellar discs. Large nano-diamonds, being the hottest, are most affected by the stellar radiation field, however, the effects of radiation pressure appear to be insufficient to move them out of harm's way. The nano-diamonds that best survive and therefore shine in the inner regions of proto-planetary discs are then seemingly small (a < 10 nm), hydrogenated, and close in size to pre-solar nano-diamonds (a ~ 1.4 nm). Nevertheless, it does not yet appear possible to reconcile their existence there with their seemingly short lifetimes in such regions.
