Does a 2,200 Å hump observed in an artificial carbonaceous composite account for UV interstellar extinction?
Does a 2,200 Å hump observed in an artificial carbonaceous composite account for UV interstellar extinction?
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在人造碳质复合材料中观察到的 2,200 Å 驼峰是否可以解释紫外线星际消光？
作者：
A. Sakata;S. Wada;Yoshiji Okutsu;H. Shintani;Y. Nakada
星际消光曲线上的2200 Å驼峰自从被Stecher1发现以来就引起了人们的广泛关注。石墨2、3和碳质颗粒4和氧化镁（参考文献5）被认为是可能的候选物质。Sakata et al.4报道了Murchison陨石（C2碳质球粒陨石）提取物的吸收光谱在2200 Å附近有一个驼峰。这个驼峰被认为是由于碳氢化合物具有共轭双键。星际灭光极有可能是由含有这种共轭双键的碳质物质引起的。在本实验中，通过向真空室注入氢和碳的等离子体混合气体来合成碳质材料。在1900 - 7000的范围内测量了材料的消光Å。合成材料的消光曲线明显表现为2,200 Å峰，中心波长的平均值为2,170±30Å。
The 2,200 Å hump in the interstellar extinction curve has attracted much attention since its discovery by Stecher1. Graphitic2,3 and carbonaceous grains4 and MgO (ref. 5) have been considered as possible candidates. Sakata et al.4 have reported a hump near 2,200 Å in the absorption spectrum of an extract from the Murchison meteorite, a C2 carbonaceous chondrite. The hump was presumed to be due to hydrocarbons having conjugated double bonds. It is highly probable that the interstellar extinction is caused by carbonaceous materials containing such conjugated double bonds. In the present experiment, carbonaceous materials were synthesized by injecting a plasmic gas mixture of hydrogen and carbon into a vacuum chamber. Extinction of the material was measured over the range 1,900–7,000 Å. The extinction profile of the synthesized material clearly exhibits the 2,200 Å hump, the average value for the central wavelength being 2,170±30Å.