论文标题
NGC 7023中多环芳烃发射的主要成分分析
A Principal Component Analysis of polycyclic aromatic hydrocarbon emission in NGC 7023
论文作者
论文摘要
我们在6.2、7.7、7.6、11.0和11.2 $μm的6.2、7.7、8.6、11.0和11.2 $μm中进行了五个多环芳烃（PCA）的主成分分析（PCA），在反射烟雾NABULA NGC 7023中构成光dosissociation区域（PDR）和一个载体和一个载体。我们发现，只需要两个主要成分（PC）来解释PAH通量中观察到的大多数方差（98％）。第一台PC（$ PC_ {1} $）是该方差的主要驱动力，代表了总PAH排放。第二个PC（$ PC_ {2} $）与整个星云的PAHS的电离状态有关。这与NGC 2023中PAH发射的类似分析的结果是一致的。Biplots和PC与各种PAH比率的相关性表明，有两个离子频带的子集与形成一个子集的6.2和7.7 $ $ m频段，以及8.6和11.0 $ $ m $ m $ m $ m $ m bands。但是，这些子集之间的区别仅存在于PDR中。我们还对PAH通量进行了单独的PCA分析，这次仅考虑腔体的变化。这表明在腔中，$ pc_ {2} $与PAH的电荷状态无关，而可能与结构分子变化有关。
We carried out a principal component analysis (PCA) of the fluxes of five polycyclic aromatic hydrocarbon (PAH) bands at 6.2, 7.7, 8.6, 11.0, and 11.2 $μ$m in the reflection nebula NGC 7023 comprising of the photodissociation region (PDR) and a cavity. We find that only two principal components (PCs) are required to explain the majority of the observed variance in PAH fluxes (98 %). The first PC ($PC_{1}$), which is the primary driver of the variance, represents the total PAH emission. The second PC ($PC_{2}$) is related to the ionization state of PAHs across the nebula. This is consistent with the results of a similar analysis of the PAH emission in NGC 2023. The biplots and the correlations of PCs with the various PAH ratios show that there are two subsets of ionic bands with the 6.2 and 7.7 $μ$m bands forming one subset and the 8.6 and 11.0 $μ$m bands the other. However, the distinction between these subsets is only present in the PDR. We have also carried out a separate PCA analysis of the PAH fluxes, this time only considering variations in the cavity. This shows that in the cavity, $PC_{2}$ is not related to the charge state of PAHs, but possibly to structural molecular changes.
