Collaborative Research: A joint theoretical and experimental approach to low-temperature dielectronic recombination data for photoionized astrophysical environments

This research project is a collaborative effort between researchers from three universities to undertake a combined theoretical and experimental study of dielectronic recombination (DR) – a key process controlling the charge balance in astrophysical plasmas ionized by starlight. The researchers will calculate the rates of DR for astronomically important atomic ions and measure them in the laboratory to high accuracy for the low temperatures relevant to space.

Accurate DR rates are only available for a handful of elements, so the data generated in this study will allow astronomers to accurately determine the elemental abundances and ionization balance in astronomical environments. The investigators will train students in methods of advanced theoretical and experimental atomic physics research relevant to astrophysics and contribute to science outreach activities for K-12 students.

The researchers will use large-scale multi-configuration semi-relativistic and fully relativistic electronic structure calculations to determine high quality DR rate coefficients, compare them to available semi-relativistic calculations, and benchmark them to accurate experimental measurements performed in cryogenic ion storage rings. The project will systematically calculate and benchmark DR data for isoelectronic sequences with the goal of providing accurate data to atomic databases and astrophysical modeling codes.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.