Charge Exchange Induced X-ray Emission of Fe XXV and Fe XXVI via a Streamlined Model
| Autor: | D. Lyons, Patrick Dean Mullen, Phillip C. Stancil, Renata Cumbee |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Physics
High Energy Astrophysical Phenomena (astro-ph.HE) Electron capture Galactic ridge Astrophysics::High Energy Astrophysical Phenomena Galactic Center FOS: Physical sciences Astronomy and Astrophysics 01 natural sciences Spectral line Ion Quantum defect Space and Planetary Science 0103 physical sciences Emission spectrum Atomic physics Astrophysics - High Energy Astrophysical Phenomena 010306 general physics 010303 astronomy & astrophysics Electron beam ion trap |
| DOI: | 10.48550/arxiv.1602.02401 |
| Popis: | Charge exchange is an important process for the modeling of X-ray spectra obtained by the Chandra, XMM-Newton, and Suzaku X-ray observatories, as well as the anticipated Astro-H mission. The understanding of the observed X-ray spectra produced by many astrophysical environments is hindered by the current incompleteness of available atomic and molecular data -- especially for charge exchange. Here, we implement a streamlined program set that applies quantum defect methods and the Landau-Zener theory to generate total, n-resolved, and nlS-resolved cross sections for any given projectile ion/ target charge exchange collision. Using this data in a cascade model for X-ray emission, theoretical spectra for such systems can be predicted. With these techniques, Fe25+ and Fe26+ charge exchange collisions with H, He, H2, N2, H2O, and CO are studied for single electron capture. These systems have been selected as they illustrate computational difficulties for high projectile charges. Further, Fe XXV and Fe XXVI emission lines have been detected in the Galactic center and Galactic ridge. Theoretical X-ray spectra for these collision systems are compared to experimental data generated by an electron beam ion trap study. Several l- distribution models have been tested for Fe25+ and Fe26+ single electron capture. Such analysis suggests that commonly used l-distribution models struggle to accurately reflect the true distribution of electron capture as understood by more advanced theoretical methods. Comment: -Keywords: Charge Exchange; Landau-Zener; Galactic center/Galactic ridge |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|