Mid-Infrared Emission Features in the Interstellar Medium: Feature-to-Feature Flux Ratios
Mid-Infrared Emission Features in the Interstellar Medium: Feature-to-Feature Flux Ratios
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星际介质中的中红外发射特征：特征与特征通量比
DOI：
10.1086/311306
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
N. Lu
中科院分区：
文献类型：
--
作者：
N. Lu
利用银河系星际介质中有限但具有代表性的源样本和红外空间天文台公布的光谱，我们分析了以6.2、7.7、8.6和11.3 μm为中心的主要中红外发射特征（EFs）之间的通量比。在EF(6.2 μm)/EF（7.7 μm）随EF(11.3 μm)/EF（7.7 μm）的通量比-通量比图中，样品源大致形成了一个Λ-shaped轨迹，总体上反映了局部加热辐射场的硬度。但是，除了辐射场之外，可能还需要一些驱动参数来全面解释这一趋势。另一方面，EF(8.6 μm)/EF（7.7 μm）的通量比在样品源上几乎没有变化，除了两个H II区域由于“EF（8.6 μm）异常”而具有更高的比率值，这一现象显然与强远紫外辐射场的环境有关。如果在更大的数据库中得到进一步证实，这些趋势将提供关于生态环境载体如何共同应对不断变化的环境的关键信息。
Using a limited but representative sample of sources in the interstellar medium of our Galaxy with published spectra from the Infrared Space Observatory, we analyze the flux ratios between the major mid-IR emission features (EFs) centered around 6.2, 7.7, 8.6, and 11.3 μm, respectively. In a flux ratio-to-flux ratio plot of EF(6.2 μm)/EF(7.7 μm) as a function of EF(11.3 μm)/EF(7.7 μm), the sample sources form roughly a Λ-shaped locus that appears to trace, on an overall basis, the hardness of a local heating radiation field. But some driving parameters other than the radiation field may also be required for a full interpretation of this trend. On the other hand, the flux ratio of EF(8.6 μm)/EF(7.7 μm) shows little variation over the sample sources, except for two H II regions that have much higher values for this ratio because of an "EF(8.6 μm) anomaly," a phenomenon clearly associated with environments of an intense far-UV radiation field. If further confirmed on a larger database, these trends should provide crucial information on how the EF carriers collectively respond to a changing environment.