Dielectronic recombination and two-photon processes: relevance to astrophysics and precision atomic physicsONLINE ONLY

The increasing sensitivity and resolving power of X-ray spectrometers require accurate modelling of the X-ray
spectra, which is in turn built on a range of fundamental atomic data. Recent observations of Hitomi satellite
have shown inconsistencies between observations and predictions among spectral models and have identified several
atomic processes that need further improvement. Among them, we focus on two-photon (TP) emission and
dielectronic recombination (DR), which constitute the main two topics of this talk.
I will provide an overview of the theoretical framework for all TP related processes that was developed at the
group LIBPhys-UNL at the NOVA University of Science and Technology (Portugal). Special attention will be
given to the technical details and challenges inherent to the theoretical evaluation of two-photon processes.
The second part of this talk is dedicated to the experimental and theoretical effort to provide not only new
theoretical data on DR, but also benchmark it with high-precision laboratory measurements. These measurements
were performed in a well-controlled environment enabled by an electron beam ion trap (EBIT) and enable a clear
observation of DR and other resonate processes with excellent resolving power. We provide an overview of recent
research focused on the astrophysical relevant elements Fe and O.