Tootfinder

Infrared spectral signatures of light r-process elements in kilonovae
Anders Jerkstrand, Quentin Pognan, Smaranika Banerjee, Nicholas Sterling, Jon Grumer, Niamh Ferguson, Keith Butler, James Gillanders, Stephen Smartt, Kyohei Kawaguchi, Blanka Vilagos
https://arxiv.org/abs/2510.12410

Infrared spectral signatures of light r-process elements in kilonovae
A central question regarding neutron star mergers is whether they are able to produce all the r-process elements, from first to third peak. The high abundances of first-peak elements (atomic number $Z \sim 31-40$) in the solar composition means they may dominate the ejecta mass in kilonovae. We here study theoretical infrared signatures of such light elements with spectral synthesis modelling. By combining state-of-the-art NLTE physics with new radiative and collisional data for these elements,…

Lanthanide Impact on the Infra-Red Spectra of Nebular Phase Kilonovae
Quentin Pognan, Kyohei Kawaguchi, Shinya Wanajo, Sho Fujibayashi, Anders Jerkstrand
https://arxiv.org/abs/2510.12413

Lanthanide Impact on the Infra-Red Spectra of Nebular Phase Kilonovae
Nebular phase kilonovae (KNe) have significant infra-red (IR) emission thought to be mostly forbidden emission lines from rapid neutron capture (r-process) species in neutron star merger ejecta. Lanthanide elements in particular have complex atomic structures with many IR transitions. Using non-local thermodynamic equilibrium (NLTE) radiative transfer simulations, we explore the impact of lanthanides on the IR spectra of KNe in the nebular phase, exploring a parameter space of ejecta mass and l…