论文标题
phangs-jwst首先结果：测量跨多相iSM的PAH特性
PHANGS-JWST First Results: Measuring PAH Properties across the multiphase ISM
论文作者
论文摘要
多环芳烃（PAH）振动带的比率是测量PAH群体及其对恒星形成的影响的有前途的工具。 JWST上的MIRI和NIRCAM仪器的光谱带提供了一个机会，可以以前所未有的分辨率和灵敏度测量整个星系磁盘上的PAH发射特征。在这里，我们在附近三个星系的样本中介绍了该分析的第一个结果：NGC 628，NGC 1365和NGC 7496。基于在3.3、7.7和11.3 $ $ M M的特征中观察到的变化，我们推断出在不同星系环境的平均PAH大小和电离状态的变化。 F335M $ _ {\ rm PAH} $/F1130W的高值和F1130W/F770W的低值在所有三个星系中都在H II区域中测量。这表明这些区域被较热的PAH填充，/或PAH电离分数更大。我们看到了较高分子气体含量的区域中PAH大小的加热和/或变化的其他证据，以及H $α$强度较高的区域的电离增加。
Ratios of polycyclic aromatic hydrocarbon (PAH) vibrational bands are a promising tool for measuring the properties of the PAH population and their effect on star formation. The photometric bands of the MIRI and NIRCam instruments on JWST provide the opportunity to measure PAH emission features across entire galaxy disks at unprecedented resolution and sensitivity. Here we present the first results of this analysis in a sample of three nearby galaxies: NGC 628, NGC 1365, and NGC 7496. Based on the variations observed in the 3.3, 7.7, and 11.3 $μ$m features, we infer changes to the average PAH size and ionization state across the different galaxy environments. High values of F335M$_{\rm PAH}$/F1130W and low values of F1130W/F770W are measured in H II regions in all three galaxies. This suggests that these regions are populated by hotter PAHs, and/or that the PAH ionization fraction is larger. We see additional evidence of heating and/or changes in PAH size in regions with higher molecular gas content as well as increased ionization in regions with higher H$α$ intensity.
