ARE C60 MOLECULES DETECTABLE IN CIRCUMSTELLAR SHELLS OF R CORONAE BOREALIS STARS?
ARE C60 MOLECULES DETECTABLE IN CIRCUMSTELLAR SHELLS OF R CORONAE BOREALIS STARS?
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DOI：
10.1088/0004-637x/729/2/126
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发表时间：
2011-01
期刊：
影响因子：
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通讯作者：
D. A. García-Hernández;N. Rao;D. Lambert
中科院分区：
文献类型：
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作者：
D. A. García-Hernández;N. Rao;D. Lambert
北冕座R星（R Coronae Borealis，RCB）周围气体的贫氢、富氦和富碳特征被认为是C60分子形成的场所。这一建议不支持的观测报告显示，红外线转换的C60是没有看到在一个大样本的RCB星观察与红外光谱仪上的斯皮策太空望远镜。然而，在DY Cen和V854 Cen的光谱中，可以看到红外C60跃迁，并且与多环芳烃（PAH）特征混合，这两颗RCB星的氢缺乏程度最低（氢缺乏程度仅为10-100）。推测C60（和多环芳烃）在中度缺氢拱信封可能是由氢化的无定形碳的分解，但富勒烯的形成是低效的，在高度缺氢的环境中的大多数RCBs。
The hydrogen-poor, helium-rich, and carbon-rich character of the gas around R Coronae Borealis (RCB) stars has been suggested to be a site for formation of C60 molecules. This suggestion is not supported by observations reported here showing that infrared transitions of C60 are not seen in a large sample of RCB stars observed with the Infrared Spectrograph on the Spitzer Space Telescope. The infrared C60 transitions are seen, however, in emission and blended with polycyclic aromatic hydrocarbon (PAH) features in spectra of DY Cen and possibly also of V854 Cen, the two least hydrogen-deficient (hydrogen deficiency of only ∼10–100) RCB stars. The speculation is offered that C60 (and the PAHs) in the moderately H-deficient circumstellar envelopes may be formed by the decomposition of hydrogenated amorphous carbon but fullerene formation is inefficient in the highly H-deficient environments of most RCBs.