论文标题
ch $^{+} $，CH和H $ _2 $分子的检测年轻行星星云IC 4997
Detection of CH$^{+}$, CH and H$_2$ molecules in the Young Planetary Nebula IC 4997
论文作者
论文摘要
我们已经从高分辨率光谱的年轻紧凑型星云IC 4997中检测到Ch $^{+} $和CH分子吸收线。高分辨率的红外（H和K频段）频谱可在许多其他线路之间检测H $ _2 $发射线。 H $ _2 $线的激发温度为2100 K，这可能是由于信封中的紫外荧光或在恒星在AGB上弹出时弹出的中性信封之间在界面形成的冲击而导致的。建议Ch $^+$可能是由吸热反应C+H $ _2 $ $ \ rightarrow $ CH $^+$+H。
We have detected CH$^{+}$ and CH molecular absorption lines from the young compact planetary nebula IC 4997 from high resolution optical spectra. A high-resolution infra-red (H and K bands) spectrum provides detection of H$_2$ emission lines amongst many other lines. The H$_2$ lines provide an excitation temperature of 2100 K which may result from UV fluorescence in the envelope or from shocks formed at the interface between an expanding outflow of ionized gas and the neutral envelope ejected when the star was on the AGB. It is suggested that the CH$^+$ may result from the endothermic reaction C + H$_2$ $\rightarrow$ CH$^+$ + H. Intriguingly, CH$^{+}$ and also CH show a higher expansion velocity than H$_{\rm 2}$ emission suggesting they may be part of the post-shocked gas.
