Public Abstract

DE-FG02-87ER40317: RESEARCH IN NUCLEAR ASTROPHYSICS: SUPERNOVAE, COMPACT OBJECTS, AND ALGORITHMS

Award Status: Active

Institution: Research Foundation for the State University of New York d/b/a RFSUNY - Stony Brook University, Stony Brook, NY
UEI: M746VC6XMNH9
DUNS: 804878247

Most Recent Award Date: 09/23/2025
Number of Support Periods: 38
PM: Morreale, Astrid

Current Budget Period: 08/01/2025 - 05/31/2026
Current Project Period: 08/01/2025 - 05/31/2028
PI: Zingale, Michael

Supplement Budget Period: N/A

Public Abstract

Research in Nuclear Astrophysics: Supernovae, Compact Objects, and Algorithms Our research takes place at the interface between nuclear theory and astrophysics, exploring the physics of compact objects and thermonuclear explosions. We propose a comprehensive exploration of the nuclear equation of state, neutron stars (including their thermal emission and X-ray bursts), gravitational-wave observations of mergers involving neutron stars, and thermonuclear runaways novae and Type Ia supernovae, and convective burning shells in massive stars leading up to core-collapse. We continue to develop novel algorithms and tools for high-performance simulations of astrophysical phenomena as well as their microphysical inputs, including the dense matter equation of state and neutrino-matter interactions. We also build the community python library pynucastro that connects nuclear data to simulations. We explore dense matter equations of state, including constraints supplied by nuclear structure and heavy-ion experiments and astrophysical observations. We are focusing on symmetry energy and thermal properties. Our work includes the study of associated neutrino opacities and emissivities. These, together with the equation of state itself, are all important ingredients in high-performance numerical simulations. We model astrophysical observations of neutron stars, including X-ray bursts, quiescent low-mass X-ray binaries and millisecond pulsars, neutrinos from supernovae and proto-neutron stars, and gravitational waves from neutron star mergers and their electromagnetic counterparts. The goal is to infer neutron star masses, radii, moments of inertia, binding energies, tidal deformabilities and oscillation frequencies. We use these together with results from nuclear experiments to predict the behavior of dense matter and the properties of QCD, and to calibrate parameterized equations of state. We collaborate with local and international groups and propose to carry out large-scale, multi-physics numerical simulations of thermonuclear supernovae, novae, X-ray bursts, and superbursts. We provide inputs for equations of state, neutrino opacities, and theoretical support to groups simulating core-collapse supernovae, proto-neutron stars, mergers of compact objects (including their gravitational wave signals), and r-process nucleosynthesis. We are developing algorithms for the rapid, but precise, inversion of the neutron star general relativistic structure (TOV) equations, part of a project to develop alternative methods for inferring equation of state information from neutron star observations avoiding the largely unquantifiable prior uncertainties associated with the usual Bayesian inversion schemes. A critical part of our research is developing algorithms for high-performance simulations of supernovae, X-ray bursts, superbursts, and novae. We will continue development of the AMReX-Astro codes Castro and MAESTROeX (and supporting tools like pynucastro), with a particular focus on the coupling between hydro and reactions, allowing us to evolve stellar reactive flows far more efficiently than other astrophysics simulation codes. We will apply these tools to X-ray bursts, novae, Type Ia supernova, and convection in massive stars. We are strong believers in Open Science---all of our development to Castro and MAESTROeX is done in public github repositories and will benefit the nuclear astrophysics community. AMReX-Astro development will continue to target new DOE supercomputer architectures, providing the community with open tools for modeling nuclear astrophysical phenomena on CPU and GPU-based supercomputers. Our X-ray burst work will be the first multidimensional simulations to model the flame propagation across the entire surface of the star (from pole-to-pole). We will continue our development of Flash and the new more general software system Flash-X, including both improved modules for astrophysics and support for new architectures as Flash and Flash-X continue to evolve. We will also reach out to the community to support new applications in nuclear physics and astrophysics with this simulation methodology. An important part of our effort at computational science is in verification, validation, and uncertainty quantification.

Research in Nuclear Astrophysics: Supernovae, Compact Objects, and Algorithms

Our research takes place at the interface between nuclear theory and astrophysics, exploring the physics of compact objects and thermonuclear explosions. We propose a comprehensive exploration of the nuclear equation of state, neutron stars (including their thermal emission and X-ray bursts), gravitational-wave observations of mergers involving neutron stars, and thermonuclear runaways novae and Type Ia supernovae, and convective burning shells in massive stars leading up to core-collapse. We continue to develop novel algorithms and tools for high-performance simulations of astrophysical phenomena as well as their microphysical inputs, including the dense matter equation of state and neutrino-matter interactions. We also build the community python library pynucastro that connects nuclear data to simulations.

We explore dense matter equations of state, including constraints supplied by nuclear structure and heavy-ion experiments and astrophysical observations. We are focusing on symmetry energy and thermal properties. Our work includes the study of associated neutrino opacities and emissivities. These, together with the equation of state itself, are all important ingredients in high-performance numerical simulations.

We model astrophysical observations of neutron stars, including X-ray bursts, quiescent low-mass X-ray binaries and millisecond pulsars, neutrinos from supernovae and proto-neutron stars, and gravitational waves from neutron star mergers and their electromagnetic counterparts. The goal is to infer neutron star masses, radii, moments of inertia, binding energies, tidal deformabilities and oscillation frequencies. We use these together with results from nuclear experiments to predict the behavior of dense matter and the properties of QCD, and to calibrate parameterized equations of state. We collaborate with local and international groups and propose to carry out large-scale, multi-physics numerical simulations of thermonuclear supernovae, novae, X-ray bursts, and superbursts. We provide inputs for equations of state, neutrino opacities, and theoretical support to groups simulating core-collapse supernovae, proto-neutron stars, mergers of compact objects (including their gravitational wave signals), and r-process nucleosynthesis. We are developing algorithms for the rapid, but precise, inversion of the neutron star general relativistic structure (TOV) equations, part of a project to develop alternative methods for inferring equation of state information from neutron star observations avoiding the largely unquantifiable prior uncertainties associated with the usual Bayesian inversion schemes.

A critical part of our research is developing algorithms for high-performance simulations of supernovae, X-ray bursts, superbursts, and novae. We will continue development of the AMReX-Astro codes Castro and MAESTROeX (and supporting tools like pynucastro), with a particular focus on the coupling between hydro and reactions, allowing us to evolve stellar reactive flows far more efficiently than other astrophysics simulation codes. We will apply these tools to X-ray bursts, novae, Type Ia supernova, and convection in massive stars. We are strong believers in Open Science---all of our development to Castro and MAESTROeX is done in public github repositories and will benefit the nuclear astrophysics community. AMReX-Astro development will continue to target new DOE supercomputer architectures, providing the community with open tools for modeling nuclear astrophysical phenomena on CPU and GPU-based supercomputers. Our X-ray burst work will be the first multidimensional simulations to model the flame propagation across the entire surface of the star (from pole-to-pole).

We will continue our development of Flash and the new more general software system Flash-X, including both improved modules for astrophysics and support for new architectures as Flash and Flash-X continue to evolve. We will also reach out to the community to support new applications in nuclear physics and astrophysics with this simulation methodology. An important part of our effort at computational science is in verification, validation, and uncertainty quantification.