34 citations · 260 across the 20 of their papers we have counts for
21 papers
Visualizing the mass transfer flow in direct-impact accretion
Juhan Frank, Alexander Straub, Sagiv Shiber +6
We use a variety of visualization techniques to display the interior and surface flows in a double white dwarf binary undergoing direct-impact mass transfer and evolving dynamicall…
Asynchronous-Many-Task Systems: Challenges and Opportunities -- Scaling an AMR Astrophysics Code on Exascale machines using Kokkos and HPX
Gregor Daiß, Patrick Diehl, Jiakun Yan +9
Dynamic and adaptive mesh refinement is pivotal in high-resolution, multi-physics, multi-model simulations, necessitating precise physics resolution in localized areas across expan…
Preparing for HPC on RISC-V: Examining Vectorization and Distributed Performance of an Astrophyiscs Application with HPX and Kokkos
Patrick Diehl, Panagiotis Syskakis, Gregor Daiß +7
In recent years, interest in RISC-V computing architectures has moved from academic to mainstream, especially in the field of High Performance Computing where energy limitations ar…
Hydrodynamic simulations of WD-WD mergers and the origin of RCB stars
Sagiv Shiber, Orsola De Marco, Patrick M. Motl +10
We study the properties of double white dwarf (DWD) mergers by performing hydrodynamic simulations using the new and improved adaptive mesh refinement code Octo-Tiger. We follow th…
Wilf's Conjecture
Valerio De Angelis, Dominic Marcello
In a Note in this Monthly, Klazar raised the question of whether the alternating sum of the Stirling numbers of the second kind is ever zero for…
Simulating Stellar Merger using HPX/Kokkos on A64FX on Supercomputer Fugaku
Patrick Diehl, Gregor Daiß, Kevin Huck +4
The increasing availability of machines relying on non-GPU architectures, such as ARM A64FX in high-performance computing, provides a set of interesting challenges to application d…
From Task-Based GPU Work Aggregation to Stellar Mergers: Turning Fine-Grained CPU Tasks into Portable GPU Kernels
Gregor Daiß, Patrick Diehl, Dominic Marcello +3
Meeting both scalability and performance portability requirements is a challenge for any HPC application, especially for adaptively refined ones. In Octo-Tiger, an astrophysics app…
Distributed, combined CPU and GPU profiling within HPX using APEX
Patrick Diehl, Gregor Daiss, Kevin Huck +6
Benchmarking and comparing performance of a scientific simulation across hardware platforms is a complex task. When the simulation in question is constructed with an asynchronous,…
Octo-Tiger's New Hydro Module and Performance Using HPX+CUDA on ORNL's Summit
Patrick Diehl, Gregor Daiß, Dominic Marcello +5
Octo-Tiger is a code for modeling three-dimensional self-gravitating astrophysical fluids. It was particularly designed for the study of dynamical mass transfer between interacting…
Performance Measurements within Asynchronous Task-based Runtime Systems: A Double White Dwarf Merger as an Application
Patrick Diehl, Dominic Marcello, Parsa Amini +9
Analyzing performance within asynchronous many-task-based runtime systems is challenging because millions of tasks are launched concurrently. Especially for long-term runs the amou…
Octo-Tiger: A New, 3D Hydrodynamic Code for Stellar Mergers that uses HPX Parallelisation
Dominic C. Marcello, Sagiv Shiber, Orsola De Marco +5
OCTO-TIGER is an astrophysics code to simulate the evolution of self-gravitating and rotat-ing systems of arbitrary geometry based on the fast multipole method, using adaptive mesh…
Is Betelgeuse the Outcome of a Past Merger?
E. Chatzopoulos, Juhan Frank, Dominic C. Marcello +1
We explore the possibility that the star alpha Orionis (Betelgeuse) is the outcome of a merger that occurred in a low mass ratio (q = M2/M1 = 0.07 - 0.25) binary system some time i…
From Piz Daint to the Stars: Simulation of Stellar Mergers using High-Level Abstractions
Gregor Daiß, Parsa Amini, John Biddiscombe +7
We study the simulation of stellar mergers, which requires complex simulations with high computational demands. We have developed Octo-Tiger, a finite volume grid-based hydrodynami…
Numerical Simulations of Mass Transfer in Binaries with Bipolytropic Components
Kundan Kadam, Patrick M. Motl, Dominic C. Marcello +2
We present the first self-consistent, three dimensional study of hydrodynamic simulations of mass transfer in binary systems with bipolytropic (composite polytropic) components. In…
Evolving R Coronae Borealis Stars with MESA
Amber Lauer, Emmanouil Chatzopoulos, Geoffrey C. Clayton +2
The R Coronae Borealis (RCB) stars are rare hydrogen--deficient, carbon--rich supergiants. They undergo extreme, irregular declines in brightness of many magnitudes due to the form…
The role of dredge-up in double white dwarf mergers
Jan E. Staff, Brandon Wiggins, Dominic Marcello +6
We present the results of an investigation of the dredge-up and mixing during the merger of two white dwarfs with different chemical compositions by conducting hydrodynamic simulat…
A Numerical Method for Generating Rapidly Rotating Bipolytropic Structures in Equilibrium
Kundan Kadam, Patrick M. Motl, Juhan Frank +2
We demonstrate that rapidly rotating bipolytropic (composite polytropic) stars and toroidal disks can be obtained using Hachisu's self consistent field technique. The core and the…
A Very Fast And Angular Momentum Conserving Tree Code
Dominic C. Marcello
There are many methods used to compute the classical gravitational field in astrophysical simulation codes. With the exception of the typically impractical method of direct computa…
What is the Shell Around R Coronae Borealis?
Edward J. Montiel, Geoffrey C. Clayton, Dominic C. Marcello +1
The hydrogen-deficient, carbon-rich R Coronae Borealis (RCB) stars are known for being prolific producers of dust which causes their large iconic declines in brightness. Several RC…
A Numerical Method for Studying Super-Eddington Mass Transfer in Double White Dwarf Binaries
Dominic C. Marcello, Joel E. Tohline
We present a numerical method for the study of double white dwarf (DWD) binary systems at the onset of super-Eddington mass transfer. We incorporate the physics of ideal inviscid h…
A Hybrid Advection Scheme for Conserving Angular Momentum on a Refined Cartesian Mesh
Zachary D. Byerly, Bryce Adelstein-Lelbach, Joel E. Tohline +1
We test a new "hybrid" scheme for simulating dynamical fluid flows in which cylindrical components of the momentum are advected across a rotating Cartesian coordinate mesh. This hy…