Complex molecules in the L1157 molecular outflow
Complex molecules in the L1157 molecular outflow
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DOI：
10.1086/590110
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发表时间：
2008-07-01
影响因子：
7.9
通讯作者：
Bachiller, Rafael
中科院分区：
文献类型：
--
作者：
Arce, Hector G.;Santiago-Garcia, Joaquin;Bachiller, Rafael
我们报告了在年轻的原恒星外流L1157中检测到复杂的有机分子。我们确定了从HCOOCH 3，CH 3CN，HCOOH，和C2H5 OH的蓝移叶中的B1冲击的位置线，使其成为第一次，复杂的物种已被检测到对一个年轻的低质量原恒星动力的分子外流。与温暖流出气体相关的时间尺度（< 2 × 10（3）年）太短，不可能在冲击波诱导的颗粒地幔溅射后在气相中形成复杂分子。更有可能的是，复杂的物种形成在颗粒的表面，然后被抛出的颗粒地幔的冲击。在低质量星星形成区域的颗粒中形成复杂分子必须是相对有效的，我们的研究结果表明，在研究原恒星周围的复杂分子时，考虑外流的影响是重要的。大部分探测到的复杂分子相对于甲醇的相对丰度与银河系中心区域的热核和分子云相似，这表明L1157暗云中尘埃的地幔成分与这些区域的尘埃相似。
We report the detection of complex organic molecules in the young protostellar outflow L1157. We identify lines from HCOOCH3, CH3CN, HCOOH, and C2H5 OH at the position of the B1 shock in the blueshifted lobe, making it the first time that complex species have been detected toward a molecular outflow powered by a young low-mass protostar. The timescales associated with the warm outflow gas (< 2 x 10(3) yr) are too short for the complex molecules to have formed in the gas phase after the shock-induced sputtering of the grain mantles. It is more likely that the complex species formed in the surface of grains and were then ejected from the grain mantles by the shock. The formation of complex molecules in the grains of low-mass star forming regions must be relatively efficient, and our results show the importance of considering the impact of outflows when studying complex molecules around protostars. The relative abundance with respect to methanol of most of the detected complex molecules is similar to that of hot cores and molecular clouds in the Galactic center region, which suggests that the mantle composition of the dust in the L1157 dark cloud is similar to dust in those regions.