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The Astrophysical MUltiscale Software Environment (AMUSE) P-I: Portegies Zwart Co-Is: Nelemans,...
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Transcript of The Astrophysical MUltiscale Software Environment (AMUSE) P-I: Portegies Zwart Co-Is: Nelemans,...
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
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
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
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
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
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
Flow control layer (scripting language)
Gas dynamicsRadiative transport
Stellar evolution Stellar dynamics
Interface layer (scripting and high level languages)
Smoothed particles
hydrodynamics
MetropolisHastings
Monte Carlo
Henyeymulti-shell
stellar evolution
4th order Hermiteblock timestep
N-body
AMUSE
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
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
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)
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
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
QUESTIONS?
management/development plan
programmers under daily supervision of software engineer and PI
regular interaction with postdoc, who protects scientific objectives
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