First Detection of the Simplest Organic Acid in a Protoplanetary Disk
First Detection of the Simplest Organic Acid in a Protoplanetary Disk
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首次检测到原行星盘中最简单的有机酸
DOI：
10.3847/2041-8213/aad046
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
V. Taquet
中科院分区：
文献类型：
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作者：
C. Favre;D. Fedele;D. Semenov;S. Parfenov;C. Codella;C. Ceccarelli;E. Bergin;E. Chapillon;L. Testi;F. Hersant;B. Lefloch;F. Fontani;G. Blake;L. Cleeves;C. Qi;K. Schwarz;V. Taquet
小行星、彗星和行星的形成发生在星星形成的早期阶段，在原行星盘的内部。因此，该盘的化学成分可能会塑造正在形成的行星系统的性质。在这种情况下，关键是要了解是否以及什么有机分子在磁盘中合成。在这封信中，我们报告了对TW Hydrae原行星盘的甲酸（HCOOH）的第一次检测。用阿塔卡马大型毫米/亚毫米波阵列（阿尔马）在129 GHz上对trans-HCOOH 6（1，6）-5（1，5）跃迁进行了观测。我们测得的圆盘平均气相t-HCOOH柱密度为100（2-4）× 1012 cm−2，与甲醇的密度一样大。HCOOH是在原行星盘中发现的第一个含有两个氧原子的有机分子，这证明有机化学在这些物体中非常活跃，尽管很难观察到。具体来说，这种最简单的酸是合成地球上生命所使用的更复杂的羧酸的基础。
The formation of asteroids, comets, and planets occurs in the interior of protoplanetary disks during the early phase of star formation. Consequently, the chemical composition of the disk might shape the properties of the emerging planetary system. In this context, it is crucial to understand whether and what organic molecules are synthesized in the disk. In this Letter, we report the first detection of formic acid (HCOOH) toward the TW Hydrae protoplanetary disk. The observations of the trans-HCOOH 6(1,6)–5(1,5) transition were carried out at 129 GHz with Atacama Large Millimeter/Submillimeter Array (ALMA). We measured a disk-averaged gas-phase t-HCOOH column density of ∼(2–4) × 1012 cm−2, namely as large as that of methanol. HCOOH is the first organic molecule containing two oxygen atoms detected in a protoplanetary disk, a proof that organic chemistry is very active, albeit difficult to observe, in these objects. Specifically, this simplest acid stands as the basis for synthesis of more complex carboxylic acids used by life on Earth.