Inner-shell ionizations in the interstellar medium

摘要: An understanding of the dynamics interstellar matter and formation stars requires in part knowledge ionizing processes clouds intercloud medium. Observations1,2 now indicate that ionization rate per hydrogen atom, ζH, is at least 2 x 10-15 sec-1 both regimes, cloud temperatures are typically 100°K 10,000°K, respectively. Given these temperatures, some nonthermal mechanism must be invoked to explain this large value ζH; however, there exists no direct observational evidence any such mechanism.