Washington: A team of many astrophysicists have launched an ambitious new multiyear project - named AGORA (Assembling Galaxies of Resolved Anatomy) - to understand and resolve inconsistencies among different galaxy formation simulations.
The big challenge has been numerically modeling astrophysical processes over the vast range of size scales in the universe.
Supercomputer simulations are designed with three different size scales relevant to three different phenomena: star formation, galaxy formation, and the large scale structure of the universe.
Computational models of stars forming within galaxies commonly zoom in on giant molecular clouds in a volume of interstellar space tens of light-years across with a resolution (ability to distinguish details) smaller than the size of our solar system. At that scale, the computational models can take into account such details as the chemical composition of gas and dust, supernova explosions of nearby stars, and shock waves and turbulence in interstellar gas.
In contrast, cosmological simulations that trace the evolution of the cosmic web of from the Big Bang to the present day model volumes hundreds of millions of light-years across.
At such a gigantic scale, even the biggest supercomputers in the world have been limited to handling primarily simple gravitational interactions of dark matter, if the calculations are to be completed within reasonable time (months) and at affordable cost.
Lead author Ji-hoon Kim , a post-doctoral researcher at the University of California, Santa Cruz, who recently joined the California Institute of Technology, and who has been coordinating the AGORA project, said what they have been trying to achieve in the AGORA project is to apply the same fundamental rule of reproducibility to computational experiments.
He said that they will make sure that the galaxies one of them simulated are reproduced by our colleagues and if they are not reproduced, they will figure out why.
The study has been accepted for publication in The Astrophysical Journal Supplement.
