标题： 从原恒星到行星状星云的多环芳烃特征演化 显示英文标题

标题： Evolution of PAH Features from Proto- to Planetary Nebulae

摘要： 为了研究UV辐射硬化（恒星有效温度升高）过程中UIR带特征的整体演化，我们分析了32颗C-rich恒星的ISO光谱：其中包括20颗原行星状星云和12颗具有沃尔夫-拉叶中心星的行星状星云。在本文中，我们讨论了所分析天体中UIR带峰值位置的变化，并证明了“7.7”到11.3微米流量比的变化与有效温度相关（可能由于其载体电离状态的增加）。 显示英文摘要

摘要： With the aim to investigate the overall evolution of UIR band features with hardening of UV radiation (increase of the star's effective temperature) we have analysed ISO spectra for 32 C-rich stars: 20 proto-planetary nebulae and 12 planetary nebulae with Wolf-Rayet central stars. In this contribution we discuss variations in the peak position of UIR bands among analysed objects, and demonstrate that variations in the ``7.7'' to 11.3 microns flux ratio are correlated with the effective temperature (probably due to an increase of the ionization state of their carriers).