# Research Projects

### Interstellar Turbulence by Supermassive Black-Hole Jets, Winds, and Radiation

A new paradigm in AGN feedback Galaxies and the supermassive black holes at their centers are known to co-evolve through cosmic time, but how this occurs is still largely unknown. The current belief is that black holes can regulate the star-formation in galaxies by removing gas through outflows driven by...

### Origin of the diversity in galaxy evolution in proto-cluster regions

This project investigates galaxy evolution in the large-scale structure of the universe. Recent observations have revealed many distant galaxies. This has led to the discovery of a series of proto-cluster regions of galaxies in the early universe, as well as various phenomena related to galaxy evolution, such as galaxies with...

### Probing the structure and dynamics of accretion flows and outflows around black holes with radiation hydrodynamical simulations

This project aims to uncover the structure and dynamics of black hole accretion disks and the formation mechanisms of black hole jets and other outflows. Understanding the physics of black hole accretion disks and jet streams will directly lead to the understanding of the energy production mechanisms of high-energy astrophysical...

### Study of black hole spacetime and high-energy phenomena through direct comparison of theory and observation

How are black hole accretion disks, jets, and disk winds observed? Can the observations be explained? The purpose of this project is to investigate the space-time structure of black holes and high-energy phenomena in strong gravitational fields by comparing theory and observation. On the one hand, models constructed by theoretical...

### Multiple BH merger and supermassive black hole formation

Since 2016, more than 50 black hole merging events have been reported by gravitational wave observations with aLIGO+aVIRGO. The majority of these are mergers of massive black hole pairs larger than $10 M_\odot$ ($M_\odot$ is the mass of the sun). The theory of black hole mergers has so far centered...

### HPC projects

Information unavailable at present

### Multi-wavelength general relativistic ray tracing code RAIKOU

General relativistic radiative transfer (GR-RT) calculations are used to theoretically produce the radiation spectra and wavelength-specific images expected to be obtained from black hole observations. Our multi-wavelength GR-RT code RAIKOU is capable of solving the propagation of light around a black hole with extremely high accuracy and with it we...

### Development of the general relativistic radiation magneto-hydrodynamic code Inazuma

To predict the gas dynamics around a black hole, we need to perform calculations that incorporate general relativity, magnetohydrodynamics, and radiation transport, that is, general relativistic radiation magnetohydrodynamics (GR-RMHD) calculations. The only way to solve this problem is numerically using a supercomputer. To this end, we developed the world's first...

### Circularly polarized light in star-forming regions

In this project, we study the production of circularly polarized light fields in star-forming regions using radiative transfer calculations. Recent observations have revealed several star-forming regions with a circular polarization fraction exceeding 10%. When chiral amino acids are exposed to strong circular polarization, the ratio of L to D forms...

### Navier–Stokes Simulations of Dust Coagulation in a Turbulent Protoplanetary Disk

The coagulation of dust particles is a key process in planetesimal formation. However, the radial drift and bouncing barriers are not completely resolved, especially for silicate dust. Since the collision velocities of dust particles are regulated by turbulence in a protoplanetary disk, turbulent clustering should be properly treated. To that...

### The formation of amino acids in the interstellar medium

Starting with the discovery of various organic molecules including amino acids in the Murchison meteorite, the notion of an origin of life in space is gaining momentum through many new discoveries, e.g., the first observation of chiral molecules in interstellar space. Amino acids exist in L- (left-handed) and D- (right-handed)...

### Development of a fast radiative transfer code for infrared biomedical diagnosis

In this project, we are developing a fast and accurate radiative transfer code for biomedical diagnosis using near-infrared radiation, based on our experience in radiative transfer calculation in astrophysics. Currently, medical diagnostic imaging is performed in various ways in the medical applications, including X-ray, MRI, and PET. However, these methods...

### Past Projects

Information unavailable at present