Small-scale structure of the galactic cirrus emission
Small-scale structure of the galactic cirrus emission
复制标题
银河卷云发射的小尺度结构
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
C. D. Burgo
中科院分区：
文献类型：
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作者：
C. Kiss;P. Ábrahám;U. Klaas;D. Lemke;P. Héraudeau;C. D. Burgo
利用ISOPHOT在90 ~ 200µm波长范围内观测了13个天场的卷云结构的傅里叶功率谱特征，以研究光谱指数α的变化。W - e发现α随场而异，-5.3≤α≤-2.1。它取决于绝对表面亮度和氢柱密度。我们还发现，在不同波长下，同一天空区域的光谱指数也不同。波长越长，功率谱越陡。这可以用不同温度下存在的尘埃来解释，特别是冷扩展成分。对于远红外天空中最微弱的区域，我们推导出卷云功率谱的波长无关光谱指数为α = -2.3±0.6。应用正确的光谱指数是正确解开宇宙远红外背景中卷云前景分量及其起伏的先决条件。
We examined the Fourier power spectrum characteristics of cirrus structures in 13 sky fields with faint to bright cirrus emission observed with ISOPHOT in the 90-200 µm wavelength range in order to study variations of the spectral index α .W e found that α varies from field to field with -5.3 ≤ α ≤-2.1. It depends on the absolute surface brightness and on the hydrogen column density. We also found different spectral indices for the same sky region at different wavelengths. Longer wavelength measurements show steeper power spectra. This can be explained by the presence of dust at various temperatures, in particular of a cold extended component. For the faintest areas of the far-infrared sky we derive a wavelength-independent spectral index of α = -2.3 ± 0.6 for the cirrus power spectrum. The application of the correct spectral index is a precondition for the proper disentanglement of the cirrus foreground component of the Cosmic Far-Infrared Background and its fluctuations.