PHOSPHORUS-BEARING MOLECULES IN MASSIVE DENSE CORES
PHOSPHORUS-BEARING MOLECULES IN MASSIVE DENSE CORES
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DOI：
10.3847/2041-8205/822/2/l30
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发表时间：
2016-05-10
影响因子：
7.9
通讯作者：
Palau, A.
中科院分区：
文献类型：
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作者：
Fontani, F.;Rivilla, V. M.;Palau, A.
磷是生命发展的关键元素，但到目前为止，仅在少数天体中发现了含磷分子;因此，它的星际化学几乎完全未知。在这里，我们展示了新的检测到的磷氮化物（PN）在致密的核心样本在不同的演化阶段的中间和高质量的星星形成过程：无星，与原恒星的对象，并与超致密H II地区。所有探测到的PN线宽都小于或等于5 km·s（-1），它们来自于与小于100 K的动力学温度有关的区域。由于文献中报道的几个以前的检测与温暖和更多的湍流源，这项工作的结果表明，PN可以产生相对静止和冷的气体。这一信息是具有挑战性的理论模型，调用高解吸温度或晶粒溅射从冲击释放到气相中的磷。导出的柱密度为10（11-12）cm（-2）的数量级，略低于迄今为止在少数高质量恒星形成区域中检测到的值。一氧化磷的丰度，生物相关分子的基本单位，新的限制，也给出了。
Phosphorus is a crucial element for the development of life, but so far P-bearing molecules have been detected only in a few astrophysical objects; hence, its interstellar chemistry is almost totally unknown. Here, we show new detections of phosphorus nitride (PN) in a sample of dense cores in different evolutionary stages of the intermediate-and high-mass star formation process: starless, with protostellar objects, and with ultracompact H II regions. All detected PN line widths are smaller than similar or equal to 5 km s(-1), and they arise from regions associated with kinetic temperatures smaller than 100 K. Because the few previous detections reported in the literature are associated with warmer and more turbulent sources, the results of this work show that PN can arise from relatively quiescent and cold gas. This information is challenging for theoretical models that invoke either high desorption temperatures or grain sputtering from shocks to release phosphorus into the gas phase. Derived column densities are of the order of 10(11-12) cm(-2), marginally lower than the values derived in the few high-mass star-forming regions detected so far. New constraints on the abundance of phosphorus monoxide, the fundamental unit of biologically relevant molecules, are also given.