Sub-issue C: Deciphering the Universe with Large-Scale Simulations and Astronomical Big Data

Purpose and significance

An array of recent astronomical observations revealed the expansion history of the Universe and the energy content. At the same time we have come to recognize the existence of two misterious substances called dark matter and dark energy. The standard theory of structure formation in the universe posits that astronomical objects such as galaxies and black holes were formed through gravitational growth of primeval density fluctuations left over from the Big Bang. A promising approach toward understanding the formation and evolution of galaxies is to perform direct, multi-physics simulations that incorporate physics galaxy formation, such as gravity, fluid dynamics, and radiation transfer. From the perspective of computational science, there is a need to develop an efficient code that can handle diverse phenomena occurring on different length scales.
In the next ten years, a variety of large observational programs will be conducted. For example, the Subaru HSC Survey led by Japan is expected to observe 500 million galaxies, 500000 active galaxies that host super-massive black holes, and 24,000 supernovae. We will push the frontier of
big data cosmology that combines observational data and large-scale simulations to elucidate the evolution of the universe and the formation of galaxies.

Member

Chief
Yoshida Naoki: Professor, School of Science, The University of Tokyo

Member
Oogi Taira: Researcher, Kavli IPMU, The University of Tokyo
Ohsuga Ken: Assistant Professor, National Astronomical Observatory of Japan
Takahashi Hiroyuki: Assistant Professor, National Astronomical Observatory of Japan
Yoshikawa Kohji: Lecturer, Center for Computational Sciences, University of Tsukuba
Tanaka Satoshi: Research Fellow, Center for Computational Sciences, University of Tsukuba
Matsumoto Ryoji: Professor, Graduate School of Science, Chiba University
Matsumoto Yosuke: Research Associate professor, Graduate School of Science, Chiba University
Kato Yoshiaki: Research Associate, Graduate School of Science, Chiba University
Ishiyama Tomoaki: Associate Professor, Institute of Management and Information Technologies, Chiba University

Future outlook: 10 years later and beyond

  • We perform numerical simulations using 6D Boltzmann code with a high parallel efficiency.
  • We study the effects of magnetic turbulence on the evolution of accretion disks, develop a unified model of active galactic nuclei, and clarify the mechanism underlying the high-energy gamma-ray emission observed in active galaxies.
  • We measure the neutrino mass by comparing wide-field galaxy survey data and numerical simulations.