论文标题
在HH 212磁盘大气中，有机分子在行星形成量表上的分层分布
Stratified Distribution of Organic Molecules at the Planet-Formation Scale in the HH 212 Disk Atmosphere
论文作者
论文摘要
甲酰胺（NH2CHO）被认为是重要的益生元分子，因为它具有形成肽键的潜力。最近在太阳系量表上的HH 212 Protostellar磁盘的大气中检测到了它。在这里，我们在磁盘大气中绘制了它及其潜在的母体分子HNCO和H2CO，以及其他分子CH3OH和CH3CHO，研究其形成机制。有趣的是，我们发现这些分子的分层分布，外部发射半径从NH2CHO和HNCO的〜24 au增加到CH3CHO的36 au，对于CH3OH的40 au，然后用于H2CO的48 au。更重要的是，我们发现NH2CHO，CH3OH和H2CO的外部发射半径的增加顺序与其结合能的减小顺序一致，从而支持它们从冰粒上的冰层中热解剖。我们还发现，与NH2CHO的结合能低得多的HNCO具有与NH2CHO的空间分布，运动学和温度几乎相同的，因此更有可能是nh2cho的女儿种类。另一方面，我们发现H2CO具有与NH2CHO不同运动学不同的空间分布更扩展的空间分布，因此质疑它是否可以是NH2CHO的气相母体分子。
Formamide (NH2CHO) is considered an important prebiotic molecule because of its potential to form peptide bonds. It was recently detected in the atmosphere of the HH 212 protostellar disk on the Solar-System scale where planets will form. Here we have mapped it and its potential parent molecules HNCO and H2CO, along with other molecules CH3OH and CH3CHO, in the disk atmosphere, studying its formation mechanism. Interestingly, we find a stratified distribution of these molecules, with the outer emission radius increasing from ~ 24 au for NH2CHO and HNCO, to 36 au for CH3CHO, to 40 au for CH3OH, and then to 48 au for H2CO. More importantly, we find that the increasing order of the outer emission radius of NH2CHO, CH3OH, and H2CO is consistent with the decreasing order of their binding energies, supporting that they are thermally desorbed from the ice mantle on dust grains. We also find that HNCO, which has much lower binding energy than NH2CHO, has almost the same spatial distribution, kinematics, and temperature as NH2CHO, and is thus more likely a daughter species of desorbed NH2CHO. On the other hand, we find that H2CO has a more extended spatial distribution with different kinematics from NH2CHO, thus questioning whether it can be the gas-phase parent molecule of NH2CHO.
