Temperature effects on the mid- and far-infrared spectra of olivine particles
Temperature effects on the mid- and far-infrared spectra of olivine particles
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DOI：
10.1051/0004-6361:20053256
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发表时间：
2006-04-01
影响因子：
6.5
通讯作者：
Tsuchiyama, A
中科院分区：
文献类型：
--
作者：
Koike, C;Mutschke, H;Tsuchiyama, A
在5 ~ 100 μ m的红外光谱范围内，测量了不同Mg/Fe含量的橄榄石颗粒在连续冷却到10 K时的吸收光谱。分别在京都和耶拿的实验室对合成镁橄榄石、天然橄榄石和合成铁橄榄石的不同样品进行了测量。在300 K和10 K之间的区间内，在多达七个单独的温度下详细测量了这些样品的橄榄石红外带的位置。根据橄榄石谱带在不同波段的宽度不同，采用2、1、0.5、0.25、0.2和0.125 cm（-1）的光谱分辨率，以高精度地测量谱带位置。一般来说，京都和耶拿样品的能带位置及其随温度变化的位移非常一致，但一些非常强的能带的位置不同，这可能是不同粒子形状的结果。对于两个长波长的镁橄榄石带在49和69 μ m，锐化和加强的频带进行了量化。这些频带的宽度不同的京都和耶拿样品，这是讨论在不同的晶体质量和颗粒凝聚的样品。我们的新数据可以用来推导尘埃温度从观测到的峰值位置结晶硅酸盐尘埃在拱星区域。
The absorption spectra of the olivine particles of different Mg/Fe content were measured in the infrared spectral region between 5 and 100 mu m, while the particles were continuously cooled down to 10 K. Measurements independently carried out on different samples of synthetic forsterite, natural olivine, and synthetic fayalite at laboratories in Kyoto and Jena. The positions of the olivine infrared bands were measured for these samples in detail at up to seven individual temperatures in the interval between 300 K and 10 K. According to the different widths of the olivine bands in different wavelength regions, spectral resolutions of 2, 1, 0.5, 0.25, 0.2, and 0.125 cm(-1) were used in order to measure the band positions with high accuracy. While in general the band positions and their temperature-dependent shift agree very well for the Kyoto and Jena samples, the positions of some very strong bands differ, which is probably a consequence of different particle shapes. For the two long-wavelength forsterite bands at 49 and 69 mu m, the sharpening and strengthening of the bands were quantified. The widths of these bands differ for the Kyoto and Jena samples, which is discussed in terms of different crystal quality and particle coagulation of the samples. Our new data can be used to derive dust temperatures from the observed peak positions for crystalline silicate dust in circumstellar regions.