Erlangen 2018 – wissenschaftliches Programm

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A: Fachverband Atomphysik

A 33: Poster Session II

A 33.26: Poster

Mittwoch, 7. März 2018, 16:15–18:15, Redoutensaal

VUV spectroscopy of highly charged ruthenium ions of astrophysical interest — Julia I. Jäger¹, Leticia Täubert¹, •Chintan Shah¹, Lisa Loebling², Klaus Werner², and José Ramón Crespo López-Urrutia¹ — ¹Max-Plank-Institut für Kernphysik, Heidelberg, Germany — ²Eberhard Karls Universität, Tübingen, Germany

The discovery of technetium in the atmospheres of red giants constituted convincing proof that s-process nucleosynthesis is indeed occurring in evolved stars. The presence of Tc in the immediate progenitor stars can be an outstanding indicator for recent nucleosynthesis. However, the main obstacle for using Tc as an indicator is the lack of experimental as well as theoretical atomic data for high ionization stages [1, 2]. Since radioactive nature of Tc imposes a technical challenge in our experiment for now, as a first step, we decided to investigate the neighboring Ru (Z=44) ions assuming their atomic structures are the same. Using electron beam ion trap, we generated Ru^4+..6+ ions and emitted vacuum ultraviolet fluorescence was measured with 3-meter normal-incidence-monochromator. Some of the VUV lines are identified by the use of Flexible Atomic Code [3]. We further plan to implement these data in non-LTE model-atmosphere simulations computing stellar spectra that can finally be compared to ultraviolet observations obtained with space-based UV telescopes.[1] K. Werner et al., ApJL, 753, L7 (2012) [2] K. Werner et al., A&A, 574, A29 (2015) [3] M. Gu, CJP, 86, 5 (2008).