1. Jonathan Carroll-Nellenback University of Rochester

2. What is AstroBEAR History of AstroBEAR MultiPhysics Thermal Conduction Viscosity Resistivity Self Gravity

3. Actively developed at the University of Rochester Written primarily using Fortran Parallelized with MPI Grid-based AMR with arbitrary sized grids Conserves mass, momentum, energy and  B Implements various Riemann solvers, and reconstruction methods. Supports self-gravity, sink particles, resistivity, viscosity, thermal conduction, and various cooling functions. Integrated trac-wiki system with extensive documentation, ticketing system, blog posts, etc… http://clover.pas.rochester.edu

4. Originally built on top of BEARCLAW AMR engine Support for constrained transport, cooling functions, and self- gravity added between 2000 and 2009. Master-worker model of BEARCLAW engine did not allow for good scaling for AMR beyond 64 cores. From 2010 to 2011 the AMR engine was redesigned and rebuilt with the goal to scale well out to 10,000’s of cores. AstroBEAR 2.0 released in 2012 with excellent scaling performance and added support for explicit thermal conduction, resistivity, and viscosity as well as support for more complicated cooling functions and ionization Ongoing development of implicit solvers for thermal conduction, and subcycling for explicit solvers. Plans to add cylindrical coordinates, radiation transport, parallel I/O, more complicated EOS’s.

5. AMR Engine redesigned with a peer to peer model for parallelization. It utilized a distributed tree to manage AMR structure, and advance threads to overlap computation with communication.

6. Designed to be easy to use with minimal knowledge of AMR. Commonly used initial and boundary conditions are easy to generate (clumps, disks, interfaces, outflows, winds density/velocity perturbations with a given power spectra, …) Many ways to control refinement. Capable of run-time analysis of AMR data sets to produce histograms, joint pdfs, projections, spectra, totals, various diagnostics, etc… Also can be used as a highly parallel post processing tool.

7. Official release only supports explicit conduction, though implicit version has been developed and is currently being tested. Explicit version does not currently sub-cycle, so hydro time step is limited to diffusion time.

8. Hydrostatic equilibrium with cold material on top of warm material. Small velocity perturbation. As field lines bend, heat is able to flow upward, causing material to become buoyant. As buoyant material moves upward, it amplifies field line perturbations.

9. Pressure equilibrium with thermal gradient

10. Self-similar solution for Temperature Density field frozen

12. Official release only supports explicit viscosity. Explicit version does not currently sub-cycle, so hydro time step is limited to viscous time.

14. Official release only supports explicit resistivity. Explicit version does not currently sub-cycle, so hydro time step is limited to resistive time.

18. References http://arxiv.org/pdf/astro-ph/0507212v2.pdfhttp://arxiv.org/pdf/astro-ph/0507212v2.pdf (MTI) http://arxiv.org/pdf/1110.0817v1.pdfhttp://arxiv.org/pdf/1110.0817v1.pdf (Tangled Fields) http://arxiv.org/abs/0801.1403http://arxiv.org/abs/0801.1403 (Thermal Conduction) http://arxiv.org/pdf/1201.0754v1.pdfhttp://arxiv.org/pdf/1201.0754v1.pdf (MHD Viscosity)