Periodic Reporting for period 1 - NUC4SIM (Advancing nucleosynthesis predictions with modern supernova simulations)
Período documentado: 2022-10-01 hasta 2024-09-30
Core-collapse supernova (CCSN) explosions mark the end of the life of stars heavier than 10 times the mass of our sun,
they play a crucial role for our understanding of the chemical composition of the universe and they are ideal laboratories
for effects of neutrino and particle physics. Current research in astrophysics, astronomy and cosmochemistry that
makes use of theoretical CCSN models for comparing to observations, still, however, relies predominantly on one-dimensional, i.e. spherically symmetric
parameterized calculations. During the last decade, however, multi-dimensional and nearly parameter-free simulation have become possible. These advances
have demonstrated that multi-dimensional simulations predict a wide variety of conditions
that cannot be found in simple 1D models, but it remains unclear if they can solve some of the disagreements between observations and theoretical supernova models.
This project aims at advancing the state-of-the-art by calculating the detailed composition of CCSN
material (i.e. isotopic nucleosynthesis yields) based on the most recent, first-principles 3D simulations and by providing the results to the community.
Since the landscape of supernova explosions spans a wide range of possible initial conditions, such as a star's initial mass, its initial composition and its environment (e.g. in a multiple system),
a wide range of models needs to explored to capture the whole diversity of possible outcomes. This project, thus, constitutes a fist step, focussing on a few models for single stars, but it aims to provide
the key elements to easily extend the approach to illuminate the full role of supernovae for the origin of the elements.
they play a crucial role for our understanding of the chemical composition of the universe and they are ideal laboratories
for effects of neutrino and particle physics. Current research in astrophysics, astronomy and cosmochemistry that
makes use of theoretical CCSN models for comparing to observations, still, however, relies predominantly on one-dimensional, i.e. spherically symmetric
parameterized calculations. During the last decade, however, multi-dimensional and nearly parameter-free simulation have become possible. These advances
have demonstrated that multi-dimensional simulations predict a wide variety of conditions
that cannot be found in simple 1D models, but it remains unclear if they can solve some of the disagreements between observations and theoretical supernova models.
This project aims at advancing the state-of-the-art by calculating the detailed composition of CCSN
material (i.e. isotopic nucleosynthesis yields) based on the most recent, first-principles 3D simulations and by providing the results to the community.
Since the landscape of supernova explosions spans a wide range of possible initial conditions, such as a star's initial mass, its initial composition and its environment (e.g. in a multiple system),
a wide range of models needs to explored to capture the whole diversity of possible outcomes. This project, thus, constitutes a fist step, focussing on a few models for single stars, but it aims to provide
the key elements to easily extend the approach to illuminate the full role of supernovae for the origin of the elements.
The first part of the project was focussed on code development that extract the data required for nucleosynthesis post-processing from existing, large-scale 3D simulations. This required the researcher to become familiar with the data formats used for the simulation outputs and the tools needed to read and interpret the data. Making extensive use of the existing software environment already developed by the host's research group over the last years, the researcher has developed a python software package to produce tracer particle data (trajectories) from the simulation output. This code has been tested by comparing statistical properties of the extracted tracer particles data to the corresponding properties of the original simulation data. Good agreement has been found.
Further tests have been performed to ensure sufficient convergence of the tracer particle set, in particular a sufficient number of tracer particles which reflects the mass resolution, as well as suitable boundaries of the computational domain.
In a second part of the project, a nuclear reaction network code has been adjusted to process the tracer particle data produced in the first step. Making use of the host institution's access to supercomputing infrastructure, the data for one of the most recent 3D models was post-processed and a prediction for the isotopic yields for a large number of nuclear species was produced.
Software and visualization tools have been developed to interpret and present the data produced by the calculations.
The analysis of these results has confirmed previously suggested trends and has revealed the importance of the long-time evolution of supernova explosions for the nucleosynthesis of isotopes important for observations, indicating that current tensions between theoretical models and observations could be resolved by long-time simulations.
Further tests have been performed to ensure sufficient convergence of the tracer particle set, in particular a sufficient number of tracer particles which reflects the mass resolution, as well as suitable boundaries of the computational domain.
In a second part of the project, a nuclear reaction network code has been adjusted to process the tracer particle data produced in the first step. Making use of the host institution's access to supercomputing infrastructure, the data for one of the most recent 3D models was post-processed and a prediction for the isotopic yields for a large number of nuclear species was produced.
Software and visualization tools have been developed to interpret and present the data produced by the calculations.
The analysis of these results has confirmed previously suggested trends and has revealed the importance of the long-time evolution of supernova explosions for the nucleosynthesis of isotopes important for observations, indicating that current tensions between theoretical models and observations could be resolved by long-time simulations.
The project has developed software and tools to produce nucleosynthesis predictions (yields) from existing and future simulations of the host's group. These tool can be used to interpret further model in this context, which provides additional value for the simulations performed by the host's group for the whole scientific field.
The researcher's findings consolidate some of the expectations for the characteristic differences between canonical 1D simulation and the state-of-the art, self-consistent 3D simulations. This provides and important benchmark for developing more computationally efficient frameworks to produce better prediction for supernova nucleosynthesis.
The author's results have also revealed that models for the late-time multi-dimensional dynamics of supernova explosions are important to accurately predict the formation of isotopes with observable signatures, such as 44Ti. The model studied by the researcher is a promising case that suggests long-time models may solve the long-standing tension between observations of 44Ti and theoretical predictions, without additional assumptions. This result is likely to stimulate further investigations of the late phases of the explosion with multi-dimensional simulation and the development of approaches to model these late times in computationally efficient ways without the loss of physical accuracy.
The researcher's findings consolidate some of the expectations for the characteristic differences between canonical 1D simulation and the state-of-the art, self-consistent 3D simulations. This provides and important benchmark for developing more computationally efficient frameworks to produce better prediction for supernova nucleosynthesis.
The author's results have also revealed that models for the late-time multi-dimensional dynamics of supernova explosions are important to accurately predict the formation of isotopes with observable signatures, such as 44Ti. The model studied by the researcher is a promising case that suggests long-time models may solve the long-standing tension between observations of 44Ti and theoretical predictions, without additional assumptions. This result is likely to stimulate further investigations of the late phases of the explosion with multi-dimensional simulation and the development of approaches to model these late times in computationally efficient ways without the loss of physical accuracy.