Calculation of rate coefficients for the excitation of rotational energy levels of the H2CS molecule by collisions with He atoms

通过与 He 原子碰撞激发 H2CS 分子旋转能级的速率系数的计算

• 批准号: 262982349
• 负责人: Professor Dr. Wilhelm H. Kegel (†)
• 金额: --
• 依托单位: Zentrum für Astronomie und Astrophysik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 无数据
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/262982349?language=en
• 关键词: Calculation; rate; coefficients; excitation; rotational

The H2CS molecule has been observed in many interstellar clouds as well as in the circumstellar envelope of the carbon star IRC+10216. For a quantitative interpretation of the observed data one has to perform NLTE radiative transfer calculations. For such calculations one needs to know the frequencies and the transitionprobabilities of many (also non-observed) spectral lines as well as the rate coefficients for excitation and deexcitation by collisions. The goal of the present project is to calculate rate coefficients for collisions between H2CS molecules and He atoms. In interstellar space collisional excitation is dominated by collisions with H2 molecules. These may be approximated reasonably well by collisions with He atoms. The latter are easier to calculate.

H2CS分子已经在许多星际云以及碳星星IRC+10216的拱星包层中被观测到。为了对观测数据进行定量解释，必须进行NLTE辐射传输计算。对于这样的计算需要知道的频率和transitionprobabilities的许多（也未观察到）谱线，以及速率系数的激发和去激发碰撞。本项目的目标是计算H2CS分子与He原子碰撞的速率系数。在星际空间中，碰撞激发主要是与H2分子的碰撞。这些可以通过与He原子的碰撞相当好地近似。后者更容易计算。