Research

I am wondering the extreme physical conditions in this world.

What is the highest temperature realized in the world? How does very strong magnetic field affect the matter? What happens in the strong gravity?

High-energy astrophysics is a field of study to investigate such extreme conditions in the Universe.

My main interest is the observational study for the compact stars (neutron stars, black holes) with X-rays or gamma-rays.

Near the compact stars, there is very large gravity field which changes even the light direction.

When matters accrete onto compact stars, they are heated due to the release of the gravitational energy and finally emit very high energy photons.

Some of neutron stars have also very strong magnetic field (~10¹² G) which is 10000 times larger than that has been realized in the laboratory.

In more detail, my interests are:

・Detector developments towards MeV gamma-ray astrophysics

-- Development of electron-tracking Compton cameras with Si-CMOS hybrid detectors

-- Reconstruction algorithm of Compton scattering

・Line spectroscopy with high-energy resolution X-ray observations

-- Gravitational redshifted lines feature (to constrain mass and radius of neutron stars)

-- Fe Kα line and its Compton shoulder (to constrain the accretion geometry around compact stars)

・Thermalization in the accretion process

-- Hard X-rays and MeV gamma-rays from accreting black holes

・Observation of strong magnetic field

-- Cyclotron resonant scattering feature

-- QED processes

・Data science, machine learning