About Us

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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

Simultaneous Formation of the Andromeda Giant Southern Stream and the Substructures in the Andromeda Halo

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The Cold Dark Matter (CDM) model, the current standard model of structure formation, suggests that larger galaxies formed hierarchically through the collisions and mergers of dwarf galaxies. Theory predicts that during this process, diffuse, faint structures consisting of stars, known as stellar streams (elongated stellar populations), emerge in the halo...

Recent Posts

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Galaxy archaeology through the synergy of Subaru and space telescopes

Sakurako Okamoto

Over the last two decades, wide-field resolved star studies have shown a remarkable variety of stellar (sub-)structures in the halos of the Milky Way and M31, attesting to the fact that accretions have played an essential role in shaping their evolution. Pushing these studies to galaxy systems beyond the Local Group is crucial to increasing sample size and deriving representative trends. In this talk, I briefly summarize recent studies of galaxy outskirts, then introduce the ongoing survey with Subaru Telescope, the Subaru Near-Field Cosmology survey, which targets several Local Volume disk galaxies to elucidate the dependence of stellar halo properties....

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Professor Ken Ohsuga wins best faculty award 2024

Professor Ken Ohsuga, head of our group, has won the University of Tsukuba 2024 Best Faculty Member...

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Students in our group win awards!

This year, we had several students win awards: 校友会江崎賞:Erika Ogata 数理物質科学研究群長賞:Erika Ogata 物理学学位プログラムリーダー賞:Takuhiro Yuasa 学生表彰(学長表彰):Michi Shinozaki 卒研ベストプレゼンテーション賞:Shinozaki...

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Associate Professor Hidenobu Yajima wins best faculty award 2022

Associate Professor Hidenobu Yajima has won the University of Tsukuba 2022 Best Faculty Member award! The award...

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[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...

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Probing the quantum-like nature of the dark matter using observations of dwarf...

Satellite abundance in Milky Way-like halos plays a crucial role in distinguishing dark matter models, in particular,...

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Mapping the High-Redshift Universe Across Scales with the Lyman-alpha line

The Lyman-alpha emission line offers a powerful window into galaxies and their diffuse environments at high redshift....

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Early-stage Evolution of Quasi-periodic Eruptions

Quasi-Periodic Eruption (QPE) is a phenomenon in which the X-ray luminosity curve shows quasi-periodic bursts near the...

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Relativistic Godunov SPH Simulations of High-Velocity Jets from Compact Astrophysical Objects

Relativistic jets are widely observed in astronomical objects including active galactic nuclei and gamma-ray bursts. However, the...

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Looking for black holes through peculiar molecular clouds in the galactic center...

The region within a radius of approximately 200 parsecs from the Galactic Center is known as the...

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Dark matter signatures in/from the Universe

Dark matter (DM) is a mysterious energy component of our Universe which occupies about a quarter of...

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Supermassive star and supermassive black-hole formation through accretinon on cosmological scales

Supermassive black holes (SMBHs), with masses ranging from 10^6 to 10^10 solar masses (Msun), are known to...

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Spatial and spectral variation of the 12CO(J=2-1)/12CO(J=1-0) line ratio in nearby galaxies...

We present 12CO(J = 1 – 0) mapping observations over ∼1/2 of the optical disk of 12...

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Formation of Astrophysical Objects 2024

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

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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...

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Formation of Astrophysical Objects 2023

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

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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...

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Recent Work

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Tracking Star-forming Cores as Mass Reservoirs in Clustered and Isolated Regions Using Numerical Passive Tracer Particles

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Cold gas bubble inflated by a low-luminosity radio jet

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Detection of the [O I] 63 μm emission line from the z = 6.04 quasar J2054-0005

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The structure of the stellar halo of the Andromeda galaxy explored with the NB515 for Subaru/HSC - I. New insights on the stellar halo up to 120 kpc

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Survey of non-thermal electrons around supermassive black holes through polarization flips

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Impact of the Lyα radiation force on super-Eddington accretion on to a massive black hole