RUI: Low Temperature Energy Transfer Studies of Interstellar Species

本研究所的研究项目集中在研究三个天体物理感兴趣的分子：氨(NH3)、羰基硫化物(OCS)和甲醇(CH3OH)的低温碰撞和能量转移。用微波-微波双共振光谱技术和压力展宽测量方法测量了低温(10~40K)样品的能量传递碰撞过程。这项研究将研究与氦和分子氢碰撞引起的低转动能级之间的能量转移。这些研究的结果将用于测试和改进最近计算的BH3-He/H2和OCS-He/H2势能面。研究的更广泛影响将涉及到对本科生的培训，他们将通过暑期研究经验和高级研究项目参与其中。测量结果对于理解冷星际分子云中氨、羰基硫化物和甲醇碰撞的动力学以及分析最近观察到的捕获在液氦液滴中的氨和羰基硫化物也将是重要的。对甲醇的研究可能有助于揭示泵送某些类型星际甲醇脉泽的机制。

This RUI research project focuses on the investigation of low temperature collisions and energy transfer of three molecules of astrophysical interest: ammonia (NH3), carbonyl sulfide (OCS), and methanol (CH3OH). Energy-transferring collisional processes are to be measured by microwave-microwave double resonance spectroscopic techniques and pressure broadening measurements in low-temperature (10 to 40 K) samples in a cell. The studies will investigate energy transfer among low-lying rotational levels induced by collisions with helium and molecular hydrogen. The results of these studies will be used to test and refine recently calculated BH3-He/H2 and OCS-He/H2 potential energy surfaces. The broader impact of the research will involve the training of undergraduate students who will participate through summer research experiences and senior research projects. Results of the measurements will also be important to the understanding of the dynamics of ammonia, carbonyl sulfide and methanol collisions in cold interstellar molecular clouds and to an analysis of recent observations of ammonia and carbonyl sulfide trapped in liquid helium droplets. The methanol studies may shed light on the mechanism for pumping certain types of interstellar methanol masers.