The chemistry of planet-forming regions is not interstellar.
The chemistry of planet-forming regions is not interstellar.
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DOI：
10.1039/c3fd00141e
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发表时间：
2014-06
影响因子：
3.4
通讯作者：
K. Pontoppidan;S. M. Blevins
中科院分区：
文献类型：
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作者：
K. Pontoppidan;S. M. Blevins
红外线和亚毫米波技术的进步使得人们能够对原行星盘的行星形成区域的分子含量进行详细的观测。特别是，围绕太阳型恒星的圆盘现在有越来越多的分子库存，可以直接与星前化学和早期太阳星云的推断进行比较。这些数据直接解决了一个老问题，即行星形成物质的化学性质与致密云和原恒星包层的化学性质是相似还是不同和独特的。这个问题的答案可能会对行星系统的结构和组成产生深远的影响。实际的挑战是，从磁盘的发射线的观测不容易转化为化学浓度。在这里，我们提出了一个二维的辐射传输模型RNO 90，一个经典的原行星盘周围的太阳质量的星星，并检索的浓度占主导地位的分子载体的碳，氧和氮在陆地区域周围的1 Au。我们比较我们的研究结果的化学库存稠密的云和原恒星信封，并认为，内部磁盘化学是，正如预期的那样，从星前化学根本不同。我们发现，最清晰的判别可能是CO2的浓度，这是非常低的磁盘，但最丰富的成分之一，致密的云和原恒星的信封。
Advances in infrared and submillimeter technology have allowed for detailed observations of the molecular content of the planet-forming regions of protoplanetary disks. In particular, disks around solar-type stars now have growing molecular inventories that can be directly compared with both prestellar chemistry and that inferred for the early solar nebula. The data directly address the old question of whether the chemistry of planet-forming matter is similar or different and unique relative to the chemistry of dense clouds and protostellar envelopes. The answer to this question may have profound consequences for the structure and composition of planetary systems. The practical challenge is that observations of emission lines from disks do not easily translate into chemical concentrations. Here, we present a two-dimensional radiative transfer model of RNO 90, a classical protoplanetary disk around a solar-mass star, and retrieve the concentrations of dominant molecular carriers of carbon, oxygen and nitrogen in the terrestrial region around 1 AU. We compare our results to the chemical inventory of dense clouds and protostellar envelopes, and argue that inner disk chemistry is, as expected, fundamentally different from prestellar chemistry. We find that the clearest discriminant may be the concentration of CO2, which is extremely low in disks, but one of the most abundant constituents of dense clouds and protostellar envelopes.