The AMAZE code package
by
Doris Folini and
Rolf Walder

Page contentsAbstractAMRCART TR3D D3NEBEL Visualization Scripts Access References Acknowledgments 
AbstractThis page contains a brief survey of the AMAZE code package. For details on each of its parts use the links in the appropriate sections below.The AMAZE code package comprises three sets of codes:
Some instructions on how to run the codes comes with the codes themselves. A brief documentation of AMRCART is also available online. Some general information and documentation exists in the form of a series of talks we have given at an 'atélier numérique' at Observatoire Paris Meudon, and some published articles. Finally, we would like to acknowledge the essential contributions of many other people, friends, collaborators, and students, to the development of AMAZE. AMRCARTAMRCART consists of a set of highly flexible codes to compute magnetic and radiative flows from one up to three space dimensions. It makes use of highresolution finite volume integrators (either Riemannsolver based or using a stabilized LaxFriedrichs method). We have implemented the adaptive mesh refinement algorithm of Berger, which automatically adjusts the spatial and temporal discretization where a higher resolution is needed. MHDfluxes are treated as suggested by Powell, ensuring the magnetic field to be divergencefree up to numerical truncation errors. The code was developed by Walder on the basis of a 2D adaptive hydrocode provided by Berger and LeVeque. It is user friendly in the sense that a new problem requires adapting three subroutines only. Want some more information on AMRCART?AMRCART has been extensively used by the Zürich stellar astrophysics group as well as by some other people. Links to some results and publications: Symbiotic binaries, WR+O binaries, Shock bound slabs, and Molecular clouds. TR3DTR3D solves the 3D, optically thick, nonrelativistic, stationary, frequency decoupled, and unpolarized NLTE radiative transfer problem for moving media. The code computes the NLTE level populations and the mean intensity at each grid point.The transfer part and the rate equation part of the problem are iteratively coupled. For the solution of the transfer part, a generalized mean intensity approach is used, which follows the idea of Turek. Its advantages are the independence of the convergence properties on the grid spacing and the moderate memory requirements. In the use of this approach lies the main difference to other existing solution methods. For the solution of the rate equation part standard techniques are used. For the treatment of optically thick lines Sobolev coefficients, adapted to three dimensions, are used. The input data consist of a 3D density, velocity, and temperature distribution, one or several radiation sources, and atomic data. Want some more information on TR3D? Links to some first applications and publications: windwind collision in gamma Velorum. Note that TR3D is a newly developed code which, although working, is still in a somewhat experimental phase. Its use, therefore, requires some effort and experience with regard to simulations, codes, and numerics. D3NEBELD3NEBEL solves the 3D, optically thin (nebular conditions), stationary NLTE radiative transfer problem for moving media. The code computes the ionization structures and Doppler broadened line profiles as seen by different observers.In D3NEBEL 3D is achieved through a set of 1D rays, all emerging from the same source of radiation. Along each 1D ray the transfer part and the rate equation part are coupled iteratively. Automatic adaptation of the spatial step size guarantees the capturing of ionization fronts. A variety of atomic processes are taken into account. The input data consist of a 3D density and velocity distribution, a radiation source, and atomic data. Matter temperatures are either computed consistently or given as input data. Want some more information on D3NEBEL? Over decades, the progenitor codes of D3NEBEL have been developed and applied by the Zürich stellar astrophysics. Although less used so far, D3NEBEL greatly benefits from these experiences. Links to some results and publications: Symbiotic binaries. VisualizationIn close collaboration with the authors of AMAZE, Dr. Jean Favre from CSCS has developed tools for fast visualization of timedependent, hierarchical, multiblock data as well as for the generation of movies.These tools are on top of the opensource graphics package ParaView and VisIt. ScriptsA variety of Unix scripts (perl, csh, tcsh) have been developed to facilitate the administration of the numerical simulations. This includes scripts for the adaptation of input files, the annotation and storage of output files, and various issues related to graphics. Small Fortran programs provide the intersection between the different codes with their different input and output data.AccessThe AMAZE code package may be available upon request. Please send email to both authors.ReferencesR. Walder and D. FoliniAMAZE: A code package to compute 3D magnetic flows, 3D NLTE radiative transfer, and synthetic spectra in Thermal and Ionization Aspects of Flows from Hot Stars: Observations and Theory, ASP Conference Series 204, p. 281284, 2000 pdffile D. Folini, R. Walder, M. Psarros and A. Desboeufs A new method for 3D radiative transfer with adaptive grids in Stellar atmosphere modeling, PASP Conference Series 288, p. 433436, 2003 pdffile D. Folini and R. Walder 3D radiative transfer under conditions of non local thermodynamic equilibrium: A contribution to the numerical solution in Hyperbolic Problems: Theory, Numerics, Applications; Editors: M.Fey and R.Jeltsch; p. 305314, 1999 pdffile J. Favre, R. Walder, and D. Folini Visualization of Astrophysical Data with AVS/Express CRAY User Conference, Stuttgart, 1998 pdffile D. Folini Computational approaches to multidimensional radiative transfer and the physics of radiative colliding flows PhD Thesis, ETH No. 12606, 1998 pdffile R. Walder Some Aspects of the Computational Dynamics of Astrophysical Nebulae PhD Thesis, ETH No. 10302, 1994 AcknowledgmentsThe development of the AMAZE code package greatly benefited from the collaboration with Marsha Berger, Jean M. Favre, Randy LeVeque, KehMing Shyue, Klaus Jürgen Ressel, and Eric de Sturler. We are indebted to the Seminar of Applied Mathematics of ETHZ and its Professors Rolf Jeltsch, Jürg Marti, and Christoph Schwab for steady scientific support and for providing positions. We thank Harry Nussbaumer for devoting positions to code development. We thank Alexandre Desboeufs, Jean Heyvaerts, Guido Kanschat, Bruno Loepfe, Daniel Megert, Simin Motamen, Ronny Peickert, Michael Psarros, Phil Roe, and Peter Steiner for their contribution. 
Send comments to authors of AMAZE: doris.folini@enslyon.fr and rolf.walder@enslyon.fr 
Last Update: October 19, 2010 