论文标题
h $ _ {2} $ o和h $ _ {2} $去除激发状态磷原子的实验研究：对恒星风中PO形成的影响
Experimental study of the removal of excited state phosphorus atoms by H$_{2}$O and H$_{2}$: implications for the formation of PO in stellar winds
论文作者
论文摘要
原子磷的低洼亚稳态，P（$^2 $ d）和P（$^2 $ p）的反应，并通过脉冲激光照射的248 nm nm的PCL $ _ {3} $ _ {3} $ _ {3} $ _ {2} $ _ {2} $ o和h $ _ {2} $的反应，与PCL $ _ {3} $^$^$^$ d lasection plase combine d lase in combine d Dis（ p（$^2 $ p）和po。测量了291至740 K之间的费率系数，以及从P（$^2 $ d或$^2 $ p） + H $ _ {2} $ o的PO生产的收益率（35 $ \ pm $ 15）。 h $ _ {2} $相对有效地与两个激发的P状态反应；物理（即碰撞）淬火，而不是对产生的pH + H的化学反应，被证明是更可能的途径。然后，使用电子结构理论计算和对复杂势能表面上发生的反应的主方程处理的组合开发了一个全面的磷化学网络。最终的模型表明，在富含氧气的条件下Mira变量AGB星星的两个恒星半径内，在P（$^2 $ d）上对地面P（$^4 $ S）的碰撞激发，随后是H $ _ {2} $ O的反应，是对PO的重要途径（以及PO之间的重要途径（以及P之间的PO）（$^4 $ s）（oh oh oh oh s）（oh oh s）（$^4 $^4 $^4 $^4 $^4 $^4。该模型还表明，在稳定（非脉动）流出中的Pn分数丰度被约2个数量级的预测不足。但是，在令人震惊的条件下，在4000 K以上的温度下发生足够的热解离，结果n原子将大部分PO转化为PN。
The reactions of the low-lying metastable states of atomic phosphorus, P($^2$D) and P($^2$P), with H$_{2}$O and H$_{2}$ were studied by the pulsed laser photolysis at 248 nm of PCl$_{3}$ , combined with laser induced fluorescence detection of P($^2$D), P($^2$P) and PO. Rate coefficients between 291 and 740 K were measured, along with a yield for the production of PO from P($^2$D or $^2$P) + H$_{2}$O of (35$\pm$15)%. H$_{2}$ reacts with both excited P states relatively efficiently; physical (i.e. collisional) quenching, rather than chemical reaction to produced PH + H, is shown to be the more likely pathway. A comprehensive phosphorus chemistry network is then developed using a combination of electronic structure theory calculations and a Master Equation treatment of reactions taking place over complex potential energy surfaces. The resulting model shows that at the high temperatures within two stellar radii of a MIRA variable AGB star in oxygen-rich conditions, collisional excitation of ground-state P($^4$S) to P($^2$D), followed by reaction with H$_{2}$O, is a significant pathway for producing PO (in addition to the reaction between P($^4$S) and OH). The model also demonstrates that the PN fractional abundance in a steady (non-pulsating) outflow is under-predicted by about 2 orders of magnitude. However, under shocked conditions where sufficient thermal dissociation of N$_2$ occurs at temperatures above 4000 K, the resulting N atoms convert a substantial fraction of PO to PN.
