3D Radiation Hydrodynamics

1. P5 P3 Source Target P2 E4 E1 E2 E3 E5 P1 P4 Radiation Hydrodynamics with HMCS HMCS realizes 3D Radiation Hydrodynamics  CP-PACS solves Smoothed Particle Hydrodynamics (SPH) and Radiation Transfer.  GRAPE-6 calculates Self-Gravity and return it to CP-PACS via PAVEMENT/PIO. 3D Radiation Hydrodynamics Smoothed Particle Hydrodynamics CP-PACS Radiation Transfer PAVEMENT/PIO Direct Summation of Self-Gravity GRAPE- 6 SPH SPH (Smoothed Particle Hydrodynamics) is a full Lagrange method to treat hydrodynamics in multi-dimension, where physical quantities are expressed by the superposition of smoothed particles with a kernel. Radiative Transfer with SPH To solve radiation transfer, smoothed particles nearest from a line between a source and a target are traced and the optical depth is assessed by the sum of relevant particles.

2. 3D Radiation-SPH Simulation on Galaxy Formation Cosmic History Galaxy Formation is simulated in weak or strong UV background radiation with HMCS. Big Bang Results depends on UV intensity !  Weak UV allows stars to form quickly. Resultantly, elliptical galaxies are born.  Strong UV retards star formation. Eventually, spiral galaxies forms. 10-44 sec Cosmic Recombination 0.1Myr Weak UV case Strong UV case Initial Cosmic Reionization Initial 0.5Gyr Galaxy Formation 2Gyr Birth of SUN 10Gyr Final Final 15Gyr (Present Day) white dots = stars, red dots = ionized gas, green dots = cold gas