Periodic Reporting for period 3 - SUPERSPEC (Three-dimensional spectral modelling of astrophysical transients : unravelling the nucleosynthetic content of supernovae and kilonovae)
Reporting period: 2022-10-01 to 2024-03-31
The objective of SUPERSPEC is to advance the state-of-the-art in transient spectral modelling both for the microphysics and macrophysics. This is achieved through parallel developments for the treatment of microphysical processes like time-dependent energy flows and new r-process atomic data, and macrophysical ones like 3D effects. These new models are then to be used to make inferences of both core-collapse supernova and kilonova nucleosynthesis.
For our society, the SUPERSPEC project will make an important contribution to better understanding the origin of the elements in the Universe - a pillar of modern astrophysics and for our sense of our origins in cosmos. It also plays a role in connecting areas in the emerging and revolutionary field of multi-messenger astronomy.
* Development and application of a time-dependent treatment for the energy and ionization equations.
* Development of a 3D code to the point that Non-Local-Thermodynamic-Equilibrium ionization, excitation, and temperature can be calculated in the limit of weak diffuse radiation field.
* A scattering-by-scattering line transfer code has been developed to study the Sobolev approximation and its degree of validity.
* The modelling of hydrogen-stripped (Type Ib) supernovae in 3D is underway.
* The modelling of superluminous supernovae (SLSNe) is underway.
* Physical conditions of kilonova ejecta has been modelled in detail, and spectral modelling is underway.
* Build-up of nebular data samples is ongoing.
In the remaining 2.5 years we aim to:
* Calculate (1D) KN model grids and draw inferences of AT2017gfo, as well as make useful predictions over parameter space for the upcoming LIGO O4 period.
* Perform crucial atomic data calculations for r-process processes including collision strengths and recombination rates.
* Produce a suite of 3D core-collapse supernova models, initially for Type Ibc supernovae and then for Type II SNe.
* Provide tests to the hypothesis of whether superluminous supernovae can be powered by pulsar wind nebulae.
* Provide a statistical analysis of the hydrostatic element production in Type II supernovae using 1D models.
* Implement self-consistent time-dependent thermalization physics - useful for both supernova and kilonova modelling.