和 英 
About Us
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
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
The Development of Self-Consistent Dust and Non-LTE Line Radiative Transfer with SKIRT and Its Application to Hydrodynamic Simulations
Kosei Matsumoto
Over the past two decades, Herschel, ALMA, and JWST have conducted detailed spectroscopic observations of molecular and atomic lines against the dust continuum, offering insights into the interstellar medium of galaxies. To interpret these observations, it is essential to self-consistently model the radiation field, the level populations of atoms and molecules, and the resulting line spectra. This approach is called non-local thermodynamic equilibrium (non-LTE) line radiative transfer. However, previous radiative transfer codes did not account for the dust continuum in the radiation field, making it difficult to model molecular and atomic line spectra, particularly at infrared wavelengths ($\lambda < 500...
[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...
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...
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...
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...
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...
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...
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...
Isotopic Links from ALMA Observations of Protoplanetary Disks to Ryugu Sample Return...
Isotopic ratios provide a powerful tool for understanding the origins of materials. Thanks to recent ALMA observations...
Bridging Nuclear Transients with AGNs - Insights from The Case of AT2023clx...
Supermassive black holes in galaxy cores trigger dynamical outbursts called nuclear transients. The number of such transients...
Nancy Grace Roman 宇宙望遠鏡が拓く新たな宇宙像 Nancy Grace Roman Space Telecope: Challenge to Open...
Nancy Grace Roman (*) 宇宙望遠鏡 (以下，Roman) の打上がいよいよ約2年後に迫ってきた。Roman は，James Webb 宇宙望遠鏡に続くNASAが主導する大型宇宙物理学ミッションで，口径2.4mの光学望遠鏡と 2.88億画素の広視野近赤外撮像・分光装置を持ち，ハッブル宇宙望遠鏡の約200倍の視野で，宇宙の加速膨張史の精密測定とダークエネルギーの性質の解明，宇宙の構造形成史の広範かつ精密な測定，太陽系外惑星の分布の全貌を把握する研究，そして，近赤外線広視野観測を活用する様々な天文学課題を遂行する。 また，Roman には，広視野での撮像分光を行う主装置 Wide Field Instrument に加えて，技術実証装置として，太陽系外惑星の直接観測のための宇宙用コロナグラフ装置が搭載される。これは将来の...
Star formation induced by cloud-cloud collisions in nearby barred galaxies
More than 300 molecular species have been identified in the interstellar matter. These chemical compositions provide various...
Formation of Astrophysical Objects 2024
This workshop aims to provide an opportunity to exchange views and share information about the current status...
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...
Formation of Astrophysical Objects 2023
This workshop aims to provide an opportunity to exchange views and share information about the current status...
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...
Recent Work
FOREVER22: Gas and metal outflow from massive galaxies in protocluster regions
Generation of high circular polarization of interstellar Lyman α radiation triggering biological homochirality
The formation of globular clusters with top-heavy initial mass functions
FOREVER22: The first bright galaxies with population III stars at redshifts z ≈ 10-20 and comparisons with JWST data
Cosmological-scale Lyα Forest Absorption around Galaxies and AGNs Probed with the HETDEX and SDSS Spectroscopic Data
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