The Numerical Methods We Used to Study Black Holes

Written by magnetosphere | Published 2024/05/10
Tech Story Tags: science | black-hole | black-hole-physics | magnetized-bonds | outer-space | galactic-nucleus | researching-outer-space | black-hole-calculations

TLDROur numerical scheme utilizes the GRMHD code KHARMA[1], a performance-portable C++ implementation based on iharm3D (Prather et al. 2021); iharm3D is itself an extension of HARM, an efficient secondorder conservative finite-volume scheme for solving MHD equations on Eulerian meshes in stationary curved space-times (Gammie et al. 2003). KHARMA offers a more flexible, portable, and scalable implementation suitable for multiple uses, by leveraging the Parthenon Adaptive Mesh Refinement Framework and the Kokkos programming model (Grete et al. 2023; Trott et al. 2022).via the TL;DR App

This paper is available on arxiv under CC 4.0 license.

Authors:

(1) Hyerin Cho (조혜린), Center for Astrophysics | Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138, USA and Black Hole Initiative at Harvard University, 20 Garden Street, Cambridge, MA 02138, USA;

(2) Ben S. Prather, CCS-2, Los Alamos National Laboratory, PO Box 1663, Los Alamos, NM 87545, USA;

(3) Ramesh Narayan, enter for Astrophysics | Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138, USA and Black Hole Initiative at Harvard University, 20 Garden Street, Cambridge, MA 02138, USA;

(4) Priyamvada Natarajan, Black Hole Initiative at Harvard University, 20 Garden Street, Cambridge, MA 02138, USA, Department of Astronomy, Yale University, Kline Tower, 266 Whitney Avenue, New Haven, CT 06511, USA and Department of Physics, Yale University, P.O. Box 208121, New Haven, CT 06520, USA;

(5) Kung-Yi Su, Center for Astrophysics | Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138, USA and Black Hole Initiative at Harvard University, 20 Garden Street, Cambridge, MA 02138, USA;

(6) Angelo Ricarte, Center for Astrophysics | Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138, USA and Black Hole Initiative at Harvard University, 20 Garden Street, Cambridge, MA 02138, USA;

(7) Koushik Chatterjee, Center for Astrophysics | Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138, USA and Black Hole Initiative at Harvard University, 20 Garden Street, Cambridge, MA 02138, USA.

Table of Links

Abstract and Introduction

Numerical Methods

Hydrodynamic Bondi Accretion

Magnetized Bondi Accretion

Feedback Via Reconnection-Driven Convection

Summary and Conclusions

Acknowledgements

Appendix

A. GRMHD Primer and Definitions

B. Numerical Set-up

C. Resolution and Initial Condition Study

References

2. NUMERICAL METHODS

Our numerical scheme utilizes the GRMHD code KHARMA[1], a performance-portable C++ implementation based on iharm3D (Prather et al. 2021); iharm3D is itself an extension of HARM, an efficient secondorder conservative finite-volume scheme for solving MHD equations on Eulerian meshes in stationary curved space-times (Gammie et al. 2003). KHARMA offers a more flexible, portable, and scalable implementation suitable for multiple uses, by leveraging the Parthenon Adaptive Mesh Refinement Framework and the Kokkos programming model (Grete et al. 2023; Trott et al. 2022).


[1] https://github.com/AFD-Illinois/kharma

[2] A few details of the numerical method are given in Section B. A complete description is deferred to a future paper.


This paper is available on Arxiv under CC 4.0 license.


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Published by HackerNoon on 2024/05/10