1. The Astrophysical MUltiscale Software Environment (AMUSE) P-I: Portegies Zwart Co-Is: Nelemans, Pols, O’Nuallain, Spaans Adv.: Langer, Tolstoy, Hut, Ercolano, de Grijs, Mellema, Spurzem, Bischof, Quillen AMUSE

2. The objectives of AMUSE More science with existing software Combine existing astrophysical codes This is a technical problem It is technically possible Impression of how it works

3. Existing codes Excellent single-physics codes exist  hydro  gravity  radiation  stellar evolution All written in different languages, different format, different architecture.... Need a homogeneous environment for utilizing these resources

4. More science with existing code Universe is multi-physics... Scientific objectives:  dense stellar systems (hydro+gravity+stellar evo.)  evolution of galactic environments, star formation, AGN,... (hydro+gravity+radiation)  planet formation (hydro+gravity+radiation)  galaxy formation and interaction (gravity+hydro+radiation+stellar evo.) Single physics software solutions exist, try to combine existing codes

5. This is a technical problem No new physics needed Combining requires understanding of how software and computer hardware interacts Development to a usefull toolbox requires professional engineering Requires substantial manpower

6. It is technically feasible Developing new code not optimal because  it is a time consuming task  large codes tend to become unmanageable  initial assumptions tend to require redesign at a late stage in the development process Combining existing code via wrapper has been tried, and works Propose homogeneous software framework, à la Numerical Recipes

7. Flow control layer (scripting language) Gas dynamics Radiative transport Stellar evolutionStellar dynamics Interface layer (scripting and high level languages) Smoothed particles hydrodynamics Metropolis Hastings Monte Carlo Henyey multi-shell stellar evolution 4 th order Hermite block timestep N-body AMUSE

8. Limitations and Merits - Only problems whose physics are expressible through module coupling (different time scales) - Low and high level use possible - Radiative transfer (and stellar evolution) module links to VO (through eg. ‘spiegel’ and ‘partiview’): dust and stellar continuum, atomic and molecular lines; ELT, JWST, ALMA, Herschel

9. Impression of how it works A) install B) suite of test applications C) design your own multi-physics problem D) write script E) run F) analyze data G) download package from website H) write Nature paper

10. Design/Performance AMUSE module must be written in language with Foreign Function Interface (C, C++, Fortran as well as high level languages like C#, Java, Haskell. Low level applications optimized. Top level uses a scripting language. These are slow, but do just I/O, GUI, call sequence. Top level can run in parallel (using MPI, GRID technology); data exchange through HDF Low level can run in parallel or on dedicated hardware (eg GRAPE or GPU for direct N-body)

11. Initial Applications Young and dense star cluster Evolution of gas and stars near a black hole in a galactic nucleus Dynamics of embryonic planets in a debris disk

12. Relation to other projects Different concept but with similar scientific objectives/physics:  FLASH  Gadget  Starlab Comparable in setup but with different scientific objectives:  Atmosphere/Ocean/Tectonic simulations by NASA  Molecular dynamics

13. QUESTIONS?

14. management/development plan programmers under daily supervision of software engineer and PI regular interaction with postdoc, who protects scientific objectives

15. The cost 6-year of programming effort (3x2years?) 2 years of software engineering 2 years of postdoc travel, webservices, hardware, etc. total cost: 640Keuro NOVA request: 500kEuro