在稠密分子云内从气态甲醇光生H $_3^+$
Photoproduction of H$_3^+$ from gaseous methanol inside dense molecular clouds
摘要：
我们目前的实验结果从丰富的星际甲醇（CH $_3$ OH）的光电离和光解离过程中获得的H $_3^+$在稠密的云生产的替代路线。这些测量是在巴西同步加速器光实验室（LNLS）采用软X射线和飞行时间质谱法进行的。质谱使用光电子-光离子符合技术获得。测定了由软X射线（C1 s边）引起的甲醇分子离解生成H $_3^+$的绝对平均截面。采用典型的软X射线发光强度和甲醇柱密度估算了H $_3^+$的光生速率和柱密度。假设一个稳定状态的情况下，最高的柱密度值为光产生的H $_3^+$约为10 $^{11}$ cm $^2$，这使得光产生/观察到的比率约为0.05%，在致密的分子云AFGL 2591的情况下。尽管数值很小，但这代表了H $_3^+$进入致密分子云的一个新的替代来源，而且在星际化学模型中还没有考虑到这一点。
英文摘要：
We present experimental results obtained from photoionization and photodissociation processes of abundant interstellar methanol (CH$_3$OH) as an alternative route for the production of H$_3^+$ in dense clouds. The measurements were taken at the Brazilian Synchrotron Light Laboratory (LNLS) employing soft X-ray and time-of-flight mass spectrometry. Mass spectra were obtained using the photoelectron-photoion coincidence techniques. Absolute averaged cross sections for the production of H$_3^+$ due to molecular dissociation of methanol by soft X-rays (C1s edge) were determined. The H$_3^+$'s photoproduction rate and column density were been estimated adopting a typical soft X-ray luminosity inside dense molecular and the observed column density of methanol. Assuming a steady state scenario, the highest column density value for the photoproduced H$_3^+$ was about 10$^{11}$ cm$^2$, which gives the ratio photoproduced/observed of about 0.05%, as in the case of dense molecular cloud AFGL 2591. Despite the small value, this represent a new and alternative source of H$_3^+$ into dense molecular clouds and it is not been considered as yet in interstellar chemistry models.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
