Showing 102 results for Author: W Raphael Hix
Sep, 2026
Journal
Numerical studies of core-collapse supernovae have demonstrated the importance of nonradial motions in precollapse progenitors on the explosion outcome. We use the Chimera neutrino radiation hydrodynamics code running seven two-dimensional simulations of 15 M⊙ progenitors with different progenitor structures introduced by different one- and two-dimensional precollapse stel…
Aug, 2026
Journal
Supernova remnant observations show a high degree of asymmetry, mixing, and inhomogeneity. These asymmetries are seeded during the early seconds of the explosion and are further enhanced and modified as the shock and ejecta move through the stellar progenitor and into the circumstellar medium. We present simulations of a 9.6 M⊙ zero-metallicity progenitor initialized after…
Aug, 2026
Journal
We present neutrino-transport algorithms implemented in the toolkit for high-order neutrino-radiation hydrodynamics (thornado) and their coupling to self-gravitating hydrodynamics within the adaptive mesh refinement (AMR)-based multiphysics simulation framework flashx. thornado, developed primarily for simulations of core-collapse supernovae (CCSNe), employs a spectral, si…
Mar, 2026
Conference Paper
Nov, 2025
Journal
The presence of a strong shallow heat source of unknown origin in accreting neutron star crusts has been inferred by analyzing x-ray observations of their cooling in quiescence. We model the cooling of KS 1731–260 using realistic crust compositions and nuclear heating and cooling sources from detailed nuclear reaction network calculations. We find that the required strengt…
Mar, 2025
Journal
T Coronae Borealis (TCrB) is a recurrent nova with recorded outbursts in 1866 and 1946 and possible outbursts in 1217 and 1787. It is predicted to explode again in 2025 or 2026 based on multiple observational studies. The system consists of a massive (Mwd ≳ 1.35 M⊙) white dwarf (WD) and a red giant (M3–M4 III). We have performed 1D hydrodynamic simulations with NOVA to pre…
Feb, 2024
Journal
We report on studies of classical nova (CN) explosions where we follow the evolution of thermonuclear runaways (TNRs) on oxygen–neon (ONe) white dwarfs (WDs). Using NOVA, a 1D hydrodynamic computer code, we accrete solar matter until the TNR is ongoing and then switch to a mixed composition. This approach is guided by the results of multidimensional studies of TNRs in WDs,…
Dec, 2023
Journal
We report on the gravitational-wave signal computed in the context of a three-dimensional simulation of a core-collapse supernova explosion of a 15 M⊙ star. The simulation was performed with our neutrino hydrodynamics code chimera. We detail the gravitational wave strains as a function of time, for both polarizations, and discuss their physical origins. We also present the…
Nov, 2023
Conference Paper
To better understand the energy generation and element synthesis occurring in novae and X‐ray bursts, we give quantitative definitions to the concepts of “bottlenecks” and “waiting points” in the thermonuclear reaction flow. We use these criteria to search for bottlenecks and waiting points in post‐processing element synthesis explosion simulations. We have incorporated th…
Nov, 2023
Journal
We investigate core-collapse supernova (CCSN) nucleosynthesis with self-consistent, axisymmetric (2D) sim- ulations performed using the neutrino hydrodynamics code CHIMERA. Computational costs have traditionally constrained the evolution of the nuclear composition within multidimensional CCSN models to, at best, a 14- species α-network capable of tracking only (α,γ) reacti…
Nov, 2023
Conference Paper
Unraveling the core-collapse supernova (CCSN) mechanism is a problem that remains essentially unsolved despite more than four decades of effort. Spherically symmetric models with otherwise high physical fidelity generally fail to produce explosions, and it is widely accepted that CCSNe are inherently multi-dimensional. Progress in realistic modeling has occurred recently t…