Electric quadrupole (E2) and magnetic dipole (M1) transitions for doubly and triply ionized krypton, xenon, and radon

Abstract

We have reported the wavelengths, transition probabilities (or rates), oscillator strengths, and line strengths for forbidden transitions (electric quadrupole, E2, and magnetic dipole, M1) in doubly and triply ionized krypton, xenon, and radon using the general-purpose relativistic atomic structure package (GRASP). The results obtained from transitions between the levels of ground state configuration are in agreement with other available results in the literature. The data on forbidden transitions between high levels for these ions have been firstly presented in this work.

Hunting for Planetary Nebulae toward the Galactic Center

“…In both candidate PNe, we detected the s-process noble gas krypton (Kr) at 2.199 µm, which was first identified in PNe by Dinerstein (2001). From the line flux measurements, we computed the Kr ++ /H + ratios of (3.67 ± 1.66) × 10 −9 and (1.36 ± 0.13) × 10 −9 for SSTGC 580183 and SSTGC 588220, respectively, based on the Br γ emissivities of Storey & Hummer (1995), the effective collisional strengths for Kr ++ of Schöning (1997), and the transition probabilities for Kr ++ of Eser & Özdemir (2019). Because [Kr III] 2.199 µm is not modeled in the current version of Cloudy, we adopted the analytical relation for the ICF from Sterling et al (2015) between the Kr ++ /Kr and the S ++ /S ratios, which show the tightest fit among other ionic ratios (such as Ar ++ /Ar).…”