EAPSI: Understanding ion-atom collisions in our Galaxy

为了提高我们对银河系天体物理学的理解，重要的是要有发生的各种过程的模型。由于电荷交换（CX）过程（离子与中性原子或分子之间的碰撞）导致的X射线发射的可靠模型目前有限。由于离子和中性氢（H）和氦（He）之间的CX的发射光谱的详细知识是必要的，以预测所得到的X射线能量依赖的光谱，我们观察到。这项研究将使用三个天体物理学上重要的碰撞系统产生的显式CX计算。然后，这些计算将以东京首都大学Hajime Tanuma博士的小组所做的测量为基准。然后，与RIKEN、大坂大学和京都大学的合作者一起，将计算出的CX光谱与使用日本朱雀望远镜观测的超新星遗迹天鹅座环的X射线观测进行比较。这将使我们深入了解天鹅座圈和其他超新星遗迹内发生的过程。这个项目将对我们理解银河系不同区域的原子碰撞和X射线辐射产生直接影响。CX是原子物理学中的一个基本过程，最近被归因于太阳系内各种天体物理环境、超新星遗迹、星暴星系和河外冷却流的X射线光谱。当离子和中性粒子都存在时，CX是一个可能发生的过程，它可能主导离子发射光谱。这项研究将使用显式CX计算产生的天体物理学重要的碰撞系统的Fe{15+}，Fe{16+}和Ne{8+}与He{+}产生的X射线发射光谱。然后，这些电荷交换数据将用于模拟天鹅座环，这是一种目前在X射线领域还没有很好理解的超新星遗迹。这个NSF EAPSI奖是与日本科学促进协会合作资助的。

In order to improve our understanding of astrophysical objects in our galaxy, it is important to have models of the various processes that occur. Reliable models of X-ray emission due to a process called charge exchange (CX), a collision between an ion and a neutral atom or molecule, are currently of limited availability. Detailed knowledge of the emission spectra due to CX between ions and neutral hydrogen (H) and helium (He) are necessary to predict the resulting X-ray energy dependent spectra which we observe. This research will use explicit CX calculations produced by three astrophysically important collision systems. These calculations will then be benchmarked to measurements done by Dr. Hajime Tanuma's group at Tokyo Metropolitan University. Then, with collaborators at RIKEN, Osaka University, and Kyoto University, the calculated CX spectra will be compared to X-ray observations of the Cygnus Loop, a supernova remnant, using observations from the Japanese telescope Suzaku. This will give us insight into the processes occurring within the Cygnus Loop and other supernova remnants. This project will have a direct impact on advancing our understanding of atomic collisions and X-ray emission in various regions of our galaxy.CX is a fundamental process in atomic physics which has recently been attributed to the X-ray spectra of various astrophysical environments within our Solar System, supernova remnants, starburst galaxies, and extragalactic cooling flows. When both ions and neutrals are present, CX is one process that can occur which may dominate the ion emission spectra. This research will use explicit CX calculations produced by the astrophysically important collision systems of Fe{15+}, Fe{16+}, and Ne{8+} with He{+} to produce the X-ray emission spectra. This charge exchange data will then be used to model the Cygnus Loop, a supernova remnant that is currently not well understood in the X-ray regime. This NSF EAPSI award is funded in collaboration with the Japan Society for the Promotion of Science.