TEMPERATURE-DEPENDENT INFRARED OPTICAL CONSTANTS OF OLIVINE AND ENSTATITE
TEMPERATURE-DEPENDENT INFRARED OPTICAL CONSTANTS OF OLIVINE AND ENSTATITE
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DOI：
10.1088/0004-637x/798/2/125
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发表时间：
2015-01
期刊：
影响因子：
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通讯作者：
S. Zeidler;H. Mutschke;Th. Posch
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文献类型：
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作者：
S. Zeidler;H. Mutschke;Th. Posch
自从红外空间观测站（ISO）的使命以来，人们已经清楚地看到，在星周盘和流出物中的尘埃部分由辉石和橄榄石类型的结晶硅酸盐组成。尘埃红外发射光谱的精确矿物学分析依赖于实验室光谱，然而，迄今为止，大多数是在室温下测量的。由于红外光谱特征取决于晶体振动模式的热激发，在各种（低和高）温度下测量的实验室光谱，对应于距离星星不同距离的热条件，可以大大提高这种分析的准确性。我们已经测量了10-973 K温度范围内每种类型硅酸盐的一种矿物的复折射率，即，橄榄石和顽火辉石的典型（陆地）组成。因此，我们的数据将以前数据的温度范围扩展到更高的值，并将成分范围扩展到更高的铁含量。我们分析了振荡器的频率和阻尼参数的温度依赖性的光谱特性的频带和计算吸收截面谱，可以与天文发射光谱。我们证明了我们的新数据的有用性，通过比较光谱计算为100 K的尘埃温度与ISO SWS光谱的IRAS 09425-6040。
Since the Infrared Space Observatory (ISO) mission, it has become clear that dust in circumstellar disks and outflows consists partly of crystalline silicates of pyroxene and olivine type. An exact mineralogical analysis of the dust infrared emission spectra relies on laboratory spectra, which, however, have been mostly measured at room temperature so far. Given that infrared spectral features depend on the thermal excitation of the crystal's vibrational modes, laboratory spectra measured at various (low and high) temperatures, corresponding to the thermal conditions at different distances from the star, can improve the accuracy of such analyses considerably. We have measured the complex refractive index in a temperature range of 10–973 K for one mineral of each of those types of silicate, i.e., for an olivine and an enstatite of typical (terrestrial) composition. Thus, our data extend the temperature range of previous data to higher values and the compositional range to higher iron contents. We analyze the temperature dependence of oscillator frequencies and damping parameters governing the spectral characteristics of the bands and calculate absorption cross-sectional spectra that can be compared with astronomical emission spectra. We demonstrate the usefulness of our new data by comparing spectra calculated for a 100 K dust temperature with the ISO SWS spectrum of IRAS 09425–6040.