About Us

Image

Our group strives to uncover the basic physics of star formation, planetary systems, active galactic nuclei, the birth of stars and galaxies of the early universe, the characteristics of the light they emit, formation and evolution of galaxies and black holes. We tackle many of the problems of modern astrophysics by solving equations of relativistic radiation hydrodynamics, radiation transport, and gravitational dynamics, which faithfully capture the interaction of light with matter and the complex gravitational interactions, so crucial in the study of the formation and evolution of stars, galaxies, and black holes. To find solutions to the complicated system of equations that describe multi-component celestial bodies and turbulent flow, we conduct large-scale numerical simulations, using, amongst others, tailor-made supercomputers at the Center for Computational Sciences.

Featured Articles

Frequency of the dark matter subhalo collisions and bifurcation sequence arising formation of dwarf galaxies

Image

Abstract The cold dark matter model predicts galaxies have 100 times more dark matter mass than stars. Nevertheless, recent observations report the existence of dark-matter-deficient galaxies with less dark matter than expected. To solve this problem, we investigate the physical processes of galaxy formation in head-on collisions between gas-containing dark...

Recent Posts

Image

ALMA and JWST exploration of high-redshift galaxies (and stars)

Yoshinobu Fudamoto

Extragalactic astronomy is currently in an exciting period. Observing high-redshift galaxies allows us to directly see galaxies in the distant past, dating back to when the Universe was only nearly a few hundred million years old. This remarkable feature has led astronomers to dedicate significant efforts toward finding and studying galaxies at high redshift to unravel the mysteries of galaxy formation and evolution in the early Universe. Particularly, over the past ten years of the Atacama Large Millimeter/submillimeter Array (ALMA) observations, combined with the recent breakthroughs from the James Webb Space Telescope (JWST), we have begun to access the extraordinarily...

image

[Press release] The Cosmic Neutrino Background: World's First Six-dimensional Simulations

In this research, we solved the Vlasov-Poisson equations directly by running our new high-precision numerical scheme for...

image

Theoretical and Observational Astrophysics Joint New Members BBQ

On the 3rd of May 2018, the Theoretical Astrophysics and the Observational Astrophysics groups organized a barbeque...

image

38th National High School Cultural Festival in Ibaraki "Ibaraki Sobun 2014"

On July 28, 2014, Yu Komatsu was interviewed by students of the newspaper division of the 38th...

Read more articles
image

State Transitions and Time Variations of Black Hole Accretion Flows

Black hole candidates display transitions between hard and soft X-ray states. During the transition, quasi-periodic oscillations and...

image

A fierce new challenge: unveiling the connection between the first galaxies and...

The Epoch of Reionization (EoR) shaped the properties of the baryonic content of the Universe. Using hydrodynamical...

image

Computing the Universe: from Intergalactic to Interstellar Medium

This talk will highlight some progress made based on our efforts of computing the universe, in order...

image

Probing dust aggregate structure in protoplanetary disks by millimeter-wave polarization

Dust coagulation in protoplanetary disks is the first step of planetesimal formation. However, a pathway from dust...

Read more articles
image

Cloud-scale molecular gas properties of nearby spiral and starburst galaxies with ALMA...

(Ultra)luminous infrared galaxies (= (U)LIRGs) at z=0 form stars 10-100 times more efficiently than z=0 main sequence...

image

X線偏光観測による活動銀河核の構造

 Active Galactic Nucleus (AGN) is a phenomenon in which the accretion of mass onto a supermassive black...

image

ダークマターは何者か?:暗黒物質の解明に向けた近傍宇宙論研究の現状と将来展望

Most of the matter in the universe is dominated by dark matter. However, its nature remains a...

image

スペクトル吸収線から探る原始銀河団ガス

In discussing the formation and evolution of galaxies, it is essential to know how the material circulation...

Read more articles
image

The grand meeting on black holes
~from stellar mass to super massive...

Almost 100 years after the prediction of general relativity, the existence of black holes has finally been...

image

Formation of Astrophysical Objects 2023

This workshop aims to provide an opportunity to exchange views and share information about the current status...

image

Black-hole jets, accretion discs, and disc-winds workshop 2023

Despite the fact that the existence of black holes is now firmly established, the structure and physical...

image

Formation of Astrophysical Objects 2022

This workshop aims to provide an opportunity to exchange views and share information about the current status...

Read more articles

Recent Work

Image
More Info

FOREVER22: Gas and metal outflow from massive galaxies in protocluster regions

Image
More Info

Generation of high circular polarization of interstellar Lyman α radiation triggering biological homochirality

Image
More Info

The formation of globular clusters with top-heavy initial mass functions

Image
More Info

FOREVER22: The first bright galaxies with population III stars at redshifts z 10-20 and comparisons with JWST data

Image
More Info

Cosmological-scale Lyα Forest Absorption around Galaxies and AGNs Probed with the HETDEX and SDSS Spectroscopic Data

Image
More Info

Morphologies of Galaxies at z 9 Uncovered by JWST/NIRCam Imaging: Cosmic Size Evolution and an Identification of an Extremely Compact Bright Galaxy at z 12