Detection of MgCN in IRC +10216: A New Metal-bearing Free Radical
Detection of MgCN in IRC +10216: A New Metal-bearing Free Radical
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DOI：
10.1086/187886
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发表时间：
1995-05
期刊：
影响因子：
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通讯作者：
L. Ziurys;A. Apponi;M. Guélin;J. Cernicharo
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文献类型：
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作者：
L. Ziurys;A. Apponi;M. Guélin;J. Cernicharo
用NRAO 12 m和IRAM 30 m望远镜在晚型星星IRC + 10216附近发现了一个新的含金属分子MgCN。N = 11的方法10，10的方法9，和9的方法8跃迁的这个物种具有（sup 2）西格玛（sup +）的基态，已被观察到在该对象的外壳在3毫米。对于N = 11的方法10跃迁，两个自旋旋转分量被清楚地解决，并最终确定这个新的自由基。这些测量值意味着外壳中的MgCN的密度柱约为10（exp 12）/cm 2，其对应于约7 × 10（exp-10）的f丰度分数。该分子是MgNO 3的亚稳异构体，是IRC + 10216外壳中迄今为止发现的第三种含金属物质，其检测表明MgNO 3/MgCN的比例约为22/1。MgCN可以通过涉及镁和HNC或CN（两者都是突出的外壳分子）的反应方案或通过在晶粒上合成来形成。
A new metal-containing molecule, MgCN, has been detected toward the late-type star IRC + 10216, using the NRAO 12 m and IRAM 30 m telescopes. The N = 11 approaches 10, 10 approaches 9, and 9 approaches 8 transtions of this species which has a (sup 2)Sigma(sup +) ground state, have been observed in the outer envelope of this object at 3 mm. For the N = 11 approaches 10 transitions, the two spin-rotation components are clearly resolved and conclusively identify this new radical. These measurements imply a column of density for MgCN of N(sub tot) approximately 10(exp 12)/sq cm in the outer shell, which corresponds to a fractional abundance of f approximately 7x10(exp -10). This molecule, the metastable isomer of MgNC, is the third metal-bearing species thus far identified in the outer shell of IRC + 10216, and its detection implies a ratio of MgNC/MgCN approximately 22/1. MgCN may be formed through a reaction scheme involving magnesium and HNC or CN, both prominent outer shell molecules, or through synthesis on grains.