Near L-edge Single and Multiple Photoionization of Doubly Charged Iron Ions
| Autor: | Jens Viefhaus, Fs-Pe, Helmholtz-Institut Jena, K. Holste, Michael Martins, Daniel Wolf Savin, Fs-Scs, R. Beerwerth, Friedrich-Schiller-Universität Jena, Alfred Müller, Sadia Bari, Kaja Schubert, Stefan Schippers, Desy, Stephan Fritzsche, Justus-Liebig-Universität Gießen |
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| Rok vydání: | 2021 |
| Předmět: |
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Absorption spectroscopy Atomic Physics (physics.atom-ph) Population FOS: Physical sciences Photoionization Astronomy & Astrophysics Atomic Ion Physics - Atomic Physics X-ray astronomy Particle and Plasma Physics Interstellar medium Ionization Nuclear Absorption (electromagnetic radiation) education Instrumentation and Methods for Astrophysics (astro-ph.IM) Interstellar atomic gas Physics Laboratory astrophysics education.field_of_study Interstellar clouds Resonance Molecular Astronomy and Astrophysics Atomic spectroscopy Space and Planetary Science Interstellar absorption ddc:520 Atomic physics Astrophysics - Instrumentation and Methods for Astrophysics Line intensities Astronomical and Space Sciences Physical Chemistry (incl. Structural) |
| Zdroj: | The Astrophysical Journal, vol 908, iss 1 The astrophysical journal / 2 908(1), 52 (2021). doi:10.3847/1538-4357/abcc64 Astrophysical Journal, vol 908, iss 1 |
| ISSN: | 1538-4357 |
| DOI: | 10.3847/1538-4357/abcc64 |
| Popis: | The astrophysical journal 908(1), 52 - (2021). doi:10.3847/1538-4357/abcc64 Using the photon-ion merged-beams technique at a synchrotron light source, we have measured relative cross sections for single and up to five-fold photoionization of Fe$^{2+}$ ions in the energy range 690--920~eV. This range contains thresholds and resonances associated with ionization and excitation of $2p$ and $2s$ electrons. Calculations were performed to simulate the total absorption spectra. The theoretical results show very good agreement with the experimental data, if overall energy shifts of up to 2.5~eV are applied to the calculated resonance positions and assumptions are made about the initial experimental population of the various levels of the Fe$^{2+}$([Ar]$3d^6$) ground configuration. Furthermore, we performed extensive calculations of the Auger cascades that result when an electron is removed from the $2p$ subshell of Fe$^{2+}$. These computations lead to a better agreement with the measured product-charge-state distributions as compared to earlier work. We conclude that the $L$-shell absorption features of low-charged iron ions are useful for identifying gas-phase iron in the interstellar medium and for discriminating against the various forms of condensed-phase iron bound to composite interstellar dust grains. Published by Univ.11032, Chicago, Ill. [u.a.] |
| Databáze: | OpenAIRE |
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