筑波大学 宇宙物理学研究室 森正夫
Theoretical Astrophysics and Computational Physics

Preface

Welcome to the website of the astrophysics research team led by Masao Mori at the University of Tsukuba. Our team advances astrophysics by combining numerical simulations, analytical theory, and observational data analysis. Research topics include galaxy formation and evolution, the role of dark matter in cosmic structure formation, galaxy collisions, supermassive black hole activity, galactic winds, and habitable zones within galaxies.

We specialise in computational astrophysics, developing large-scale simulations and theoretical models to study the complex dynamics of galaxies. Our work integrates closely with observational research, bridging theory and data to build a unified understanding of the universe. We develop high-performance hydrodynamic schemes, massively parallel algorithms, and GPU-accelerated methods, and have recently begun incorporating machine learning to further enhance astrophysical modelling.

Portrait
Campus

We are dedicated to nurturing the next generation of astrophysicists. Our group welcomes both undergraduate and graduate students, offering opportunities to participate in cutting-edge research.
At the University of Tsukuba, graduate school entrance examinations are held three times a year: a recommendation-based exam in July, and general admissions in August and February. We actively encourage applications from students at other universities as well.

Master’s students focus on building core research skills, while Ph.D. candidates pursue independent research and gain international experience through conference presentations and short-term stays abroad. They also benefit from robust support systems, including the Dual Degree Program, student funding schemes, and JSPS Research Fellowships.

I warmly welcome visitors to my laboratory, and online meetings can also be arranged. If you are interested in joining our team, please do not hesitate to contact me by email.

Masao Mori

AGSS Image

Research

My research activities so far

“How did the cosmos begin, and how did it become what it is today?” — this fundamental question has captivated humanity since ancient times. Cosmology and astrophysics seek to answer it through the lens of physics. George Gamow’s 1948 theory laid the foundation for modern discussions on the universe’s origin and has guided observational efforts throughout the 20th and 21st centuries. Today, it is widely accepted that the universe began 13.8 billion years ago in a hot, dense state—the Big Bang—and that the formation and evolution of celestial structures in the expanding universe have shaped the cosmos we observe.
Our research group aims to uncover how galaxies have evolved over cosmic time and to explore their future, grounded in the principles of natural science.

Team 2025

Activities

What's new

Here we share the latest updates on our research activities, including publications, conference presentations, media coverage, and collaborative projects. We also post about lab events and extracurricular activities that help foster connection and balance within our team.

  • June 23, 2025
    We held a collaborative research meeting with Yohei Miki, Misa Yamaguchi (D1), Akifumi Takayama (M1), and Yoshitomo Takahashi (M1) at the University of Tokyo’s Kashiwa Campus. We also toured the “MIYABI” supercomputer, which was developed in collaboration between the University of Tsukuba and the University of Tokyo.
  • June 16–20, 2025
    Yuka Kaneda (D3) presented her latest research at the international conference “Dancing in the Dark: When Galaxies Shape Galaxies,” held in Sexten, Italy.
  • May 31 – June 4, 2025
    We visited Zhejiang University in Hangzhou, China, to engage in research discussions with Dr. Go Ogiya, focusing on recent developments and exploring prospects for future collaboration.
  • May 30, 2025
    Misa Yamaguchi (D1) has been selected as a fellow in the JST SPRING Program for Challenging Exploratory Research and will receive grant-based support covering both research and living expenses. Congratulations!
  • May 26–30, 2025
    At the international conference “Expanding the Boundaries of Dark Matter Halo,” held at Shanghai Jiao Tong University, Michi Shinozaki (M1) delivered a presentation on behalf of the research team, introducing their collaborative work with Yuka Kaneda (D3) and Kohei Hayashi (Sendai KOSEN), entitled “Understanding the Cusp–Core Transition and Characteristic Radius in Dark Matter Halos."
  • May 26–30, 2025
    Yuka Kaneda (D3) presented her research titled “Split Stellar Streams as a Detector of Dark Satellites and Wandering Black Holes” at the international workshop “Galaxy Formation + AGORA in Asia 2025,” held at the Nakanoshima Center of Osaka University.
  • May 24, 2025
    The paper “Simultaneous Formation of the Andromeda Giant Southern Stream and the Substructures in the Andromeda Halo,” co-authored by Misa Yamaguchi (D1), Takanori Kirihara (Kitami Institute of Technology), Yohei Miki (University of Tokyo), Itsuki Kogami (NAOJ), Masashi Chiba (Tohoku University), Yu Komiyama (Hosei University), and Mikito Tanaka (Hosei University), has been published in PASJ. [PASJ]
About Image

About me

Who I am

Masao Mori

Ph.D. (Science), Associate Professor

  • Theoretical Astrophysics Division, Center for Computational Sciences, University of Tsukuba
  • Degree Program in Physics, Graduate School of Science and Technology, University of Tsukuba
  • Concurrent Appointment: Subprogram in Next-Generation School Education, Degree Programs in Comprehensive Human Sciences, University of Tsukuba
  • Visiting Associate Professor, University of California, Los Angeles (Feb. 2005 – Mar. 2006)
  • Visiting Researcher, Max Planck Institute for Astronomy (Aug. 1998 – Aug. 1999)
Team 2025

Our Team

Group members for this year and graduates

Below, you will find information about my current team members and graduates.

Current Members

  • Yuka Kanda(3rd-year Ph.D. & 2nd-year Master's student)
    JSPS Special Research Fellow DC1 and University of Tsukuba, Dual Degree Programme
    Challenges to the Cold Dark Matter Hypothesis (3rd-year Ph.D student in Physics)
    Structural Analysis of Stellar Streams Using Machine Learning (2nd-year master's student in Infomatics)
  • Misa Yamaguchi(1st-year Ph.D. )
    Research Fellow, JST SPRING Program for Challenging Exploratory Research
    Galaxy Collisions and Evolution of the Galactic Habitable Zone
  • Taisei Takeuchi (2nd-year Master’s)
    Formation of Star Clusters and Dark Matter Halos in the M81 Galaxy Group
  • Kotaro Hiraki (2nd-year Master’s Program in Education)
    Educational Applications through Visualisation of Astrophysical Simulations
  • Kanta Aimoto (1st-year Master’s)
    Hydrodynamical Interactions in Collisions between Satellite Galaxies and Galactic Disks
  • Mayuka Oda (1st-year Master’s)
    Scaling Relations of Massive Dark Matter Halos
  • Michi Shinozaki (1st-year Master’s)
    Critical Conditions for Cusp-Core Transitions in Dark Matter Halos
  • Yoshitomo Takahashi (1st-year Master’s)
    Development of High-Precision Hydrodynamic Simulation Schemes and Their Applications to Galaxy Formation
  • Akifumi Takayama (1st-year Master’s)
    Galaxy Mergers and Activity of Supermassive Black Hole
  • Maria Arima (4th-year Undergraduate)
    Transonic Galactic Winds in High-Redshift Galaxies
  • Taisei Nomura (4th-year Undergraduate)
    Formation of Parallel Stellar Streams in the Halo of the Andromeda Galaxy
  • Kenta Hagiwara (4th-year Undergraduate)
    Sports Science Research Utilizing Large-Scale Hydrodynamic Simulations

Achievements

Achievements

See a summary of my research Highlights

Below is a list of my recent research papers, selected papers to date, and received research funding.

Recent publications

  • Simultaneous Formation of the Andromeda Giant Southern Stream and the Substructures in the Andromeda Halo,
    Yamaguchi, Misa; Mori, Masaoi; Kirihara, Takanobu; Miki, Yohei; Ogami, Itsuki; Chiba, Masashi; Komiyama, Yutaka; Tanaka, Mikito, Publications of the Astronomical Society of Japan, 77, L36-L42 (2025) [PASJ / arXiv:2503.21217]
  • 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,
    Ogami, Itsuki, et al., Monthly Notices of the Royal Astronomical Society, 536, 530 (2025) [MNRAS / arXiv:2401.00668]
  • Cosmological evolution of dark matter subhaloes under tidal stripping by growing Milky Way-like galaxies,
    Kazuno, Yudai; Mori, Masao; Kaneda, Yuka; Otaki, Koki, PASJ, 76, L39 (2024) [PASJ / arXiv:2410.22185]
  • A universal scaling relation incorporating the cusp-to-core transition of dark matter haloes,
    Kaneda, Yuka; Mori, Masao; Otaki, Koki, PASJ, 76, 1026 (2024) [PASJ / arXiv:2407.03614]
  • Novel hydrodynamic schemes capturing shocks and contact discontinuities and comparison study with existing methods,
    Yuasa, Takuhiro; Mori, Masao, New Astronomy, 109, 102208 (2024) [New Astronomy / arXiv:2312.03224v3]
Lecture Room

Lectures

Lectures for this academic year

FY2025

  • Undergraduate Programms
    • General concept of astrophysics: Fall AB, Fri. 4
    • Hands-on Seminar for Research Exploration
    • Diploma thesis research advice

  • Postgraduate Programmes
    • Fundamental Physics 2: Fall AB, Mon. 3
    • Special Research in Astrophysics
    • Master thesis advice
    • Doctor thesis advice

  • Seminars
    • Mori's Group Seminar
    • Galaxy Seminar
    • Fundermental Physics Seminar B

Contact

Contact

Feel free to contact

mmori@ccs.tsukuba.ac.jp

Center for Computational Sciences, University of Tsukuba
Tennodai 1-1-1, Tsukuba, Ibaraki 305-8577, Japan

+81 (0)29 853 6034