论文标题
紫外光子在星际大型化学中的作用
The Role of Ultraviolet Photons in Circumstellar Astrochemistry
论文作者
论文摘要
在其渐近巨型分支阶段，在恒星进化的后期，质量在1到8个太阳能（m $ _ \ odot $）之间的恒星以气体和灰尘的形式损失了大量材料。这样的恒星在星际介质中提供多达35％的灰尘，因此有助于我们太阳系形成的材料。此外，这些恒星的折线信封是复杂的有机化学位点，其中检测到了80多个分子。我们表明，恒星本身发出的内部紫外线光子或从近距离旋转的伴侣发出的内部光子可以显着改变信封中发生的化学反应，尤其是如果信封本质上是块状的，则可能会改变。至少在这里探讨的情况下，我们发现恒星伴侣的存在，例如白矮星星，紫外光子的高通量在富含碳富含碳的AGB星星的内部摧毁了H $ _2 $ o，低于观察到的物种，并产生了与传统描述相比，在观察到的物种中，并产生了C $^+$。
Stars with masses between 1 and 8 solar masses (M$_\odot$) lose large amounts of material in the form of gas and dust in the late stages of stellar evolution, during their Asymptotic Giant Branch phase. Such stars supply up to 35% of the dust in the interstellar medium and thus contribute to the material out of which our solar system formed. In addition, the circumstellar envelopes of these stars are sites of complex, organic chemistry with over 80 molecules detected in them. We show that internal ultraviolet photons, either emitted by the star itself or from a close-in, orbiting companion, can significantly alter the chemistry that occurs in the envelopes particularly if the envelope is clumpy in nature. At least for the cases explored here, we find that the presence of a stellar companion, such as a white dwarf star, the high flux of UV photons destroys H$_2$O in the inner regions of carbon-rich AGB stars to levels below those observed and produces species such as C$^+$ deep in the envelope in contrast to the expectations of traditional descriptions of circumstellar chemistry.
