Title: Kilonovae and the cosmic origin of r-process elements: atomic structure and processes
Speaker: Sema Caliskan & Jon Grumer
Affiliation: Uppsala University
Time: Thursday 17 February 2022, 1400 to 1500
Location: 80109Å and also online at https://uu-se.zoom.us/j/62091586806 (Zoom meeting ID: 620 9158 6806)
Abstract:
The cosmic origin of elements beyond iron in the periodic table is a long standing puzzle. As such, one of the main astrophysical highlights of the last decade is without doubt the indication of rapid neutron capture (r-process) nucleosynthesis of heavy elements in the kilonova (KN) ejecta following the neutron-star (NS) merger gravitational-wave event in 2017. The analysis of KNe spectra requires information on atomic species as input to the spectral modelling of the ejecta. Reliable atomic parameters is crucial, not only to allow for direct element identifications in KN spectra, but also to determine fundamental parameters such as temperature and expansion velocity of the ejecta itself, and ultimately of the progenitor binary NS system.
However, the atomic structure and radiative properties of the neutron capture elements is largely uncharted - especially in the infrared spectral region, which is particularily prominent in KN spectra.
To tackle this lack of fundamental atomic data we will carry out theoretical and experimental investigations of the atomic structure of some selected, important neutron capture elements, with a particular focus on the near-infrared spectral region. We will then determine expansion opacities in a parameter space suitable for KNe conditions for the community to use in e.g. light curve modelling. We will also apply our atomic data in a non-local thermal equilibrium radiative transfer code to analyse the current and future KN observations.