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

Our Team

Group members for this year and graduates

Here, I introduce the members of our team, classified into current members and alumni. Since my appointment at the University of Tsukuba in April 2008, I have had the privilege of welcoming a continuous stream of talented students into the group, allowing me to be closely involved in the education and development of many young researchers.

In the Master’s programme, students acquire the theoretical foundation and practical skills essential for astrophysical research, including numerical simulations, programming, and data analysis. Through advanced coursework and individual research projects, they deepen their understanding of key topics such as cosmology and galaxy formation, while developing the ability to present and publish their work under my guidance.

Our research team actively supports individuals who, during their doctoral studies, have acquired advanced knowledge in physics, astronomy, and computational science, developed expertise in simulation techniques, visualisation, and data analysis, and are now pursuing excellence in academic or non-academic fields. We actively utilize the following programs to support research activities and enhance career paths: the University of Tsukuba Dual Degree Programme, the University of Tsukuba Doctoral Student Support Project, and the JSPS Research Fellowships.

JSPS Research Fellowships

The JSPS Fellowship provides outstanding young researchers in Japan the opportunity to devote themselves to research while independently choosing a research topic based on their own ideas. It supports their research through grants and scientific research funding.

The University of Tsukuba Doctoral Student Support Project

This program provides excellent University of Tsukuba doctoral course students with benefit-type support expenses, equivalent to living and research expenses.

The University of Tsukuba Dual Degree Programme

This programme allows doctoral students at the University of Tsukuba to also enroll in a master's programme in another specialization, enabling them to obtain both degrees simultaneously. Three students from our group have obtained a PhD in astrophysics and an MSc in High Performance Computing through this programme. Additionally, one student is currently using this scheme to conduct research in Dark Matter and Machine Learning.

Current Members

  • Misa Yamaguchi (PhD student, 2nd year)
    JSPS Research Fellow (DC2)
    Spatiotemporal Evolution of Galaxy Collisions and the Galactic Habitable Zone
  • Kanta Aimoto (MSc student, 2nd year)
    Hydrodynamic Interactions in Collisions between Galactic Disks and Satellite Galaxies
  • Mayuka Oda (MSc student, 2nd year)
    Scaling Relations and Structural Evolution of Cluster-Scale Dark Matter Halos
  • Michi Shinozaki (MSc student, 2nd year)
    Dark Matter Models Probed through the Diversity of Internal Structures in Dark Matter Halos
  • Yoshitomo Takahashi (MSc student, 2nd year)
    Development of High-Precision Hydrodynamic Schemes and Their Applications to Galaxy Formation
  • Akifumi Takayama (MSc student, 2nd year)
    Galaxy Collisions and the Activity of Supermassive Black Holes in Galactic Centers
  • Maria Arima (MSc student, 1st year)
    An Analytic Model for Galactic Outflows in Forming Galaxies in the Early Universe
  • Moeko Hori (MSc student, 1st year, Degree Program in Education)
    TBD
  • Taisei Nomura (MSc student, 1st year)
    Development and Applications of High-Precision N-Body Integration Schemes for Self-Gravitating Systems with Heterogeneous Components
  • Taisei Nishihama (Undergraduate student, 4th year)
    TBD
  • Haruto Masumitsu (Undergraduate student, 4th year)
    TBD

Graduates (Ph.D. students)

  • Yuka Kaneda
    PhD in Science, March 2026, and Master of Engineering, March 2026, through the Dual Degree Program
    Doctoral dissertation: “Investigating the Small-Scale Structure Problems in the Cold Dark Matter Framework”
    Master thesis (Science): “Scaling Relations of Dark Matter Halos and the Cusp-Core Transition”
    Master thesis (Engineering): “Estimating the Density Profiles of Dark Matter Halos from Tidal Streams Using CNNs”
    JSPS Research Fellow for Young Scientists (DC1, during enrollment)
    Current position: JSPS Postdoctoral Research Fellow at the University of Tokyo
  • Koki Otaki
    PhD in Science, March 2023, and Master of Engineering, March 2022, through the Dual Degree Program
    Doctoral dissertation: “Formation of Dwarf Galaxies Induced by Dark Matter Subhalo Collisions”
    Master thesis (Science): “Formation of Dark Matter-Deficient Galaxies Induced by Dark Matter Subhalo Collisions”
    Master thesis (Engineering): “GPU Implementation and Performance Evaluation of Hydrodynamical Simulations for Galaxy Formation”
    JSPS Research Fellow for Young Scientists (DC1, during enrollment)
    Postdoctoral Researcher at Sapienza University of Rome, Italy (until March 2026)
    Current position: Assistant Professor at the University of Tokyo (from April 2026)
  • Kazuki Kato
    PhD in Science, March 2019
    Doctoral dissertation: “Dynamics of the Cusp-to-Core Transformation in Low-Mass Galaxies and Formation of Ultra-Diffuse Galaxies”
    Current position: Employment in industry
  • Takanobu Kirihara
    PhD in Science, March 2017
    Doctoral dissertation: “Numerical Study of Internal Structures of Galaxies through Minor Merger Events in M31”
    JSPS Research Fellow for Young Scientists (DC1, during enrollment)
    Current position: Associate Professor at Kitami Institute of Technology
  • Asuka Igarashi
    PhD in Science, March 2017
    Doctoral dissertation: “Transonic Analysis of Galactic Outflows and Its Applications”
    Current position: Researcher at the National Institute of Informatics and the National Institute of Advanced Industrial Science and Technology
  • Go Ogiya
    PhD in Physics, March 2014, and Master of Engineering, March 2013, through the Dual Degree Program
    Doctoral dissertation: “Solving the Core-Cusp Problem of Cold Dark Matter Halos and the Origin of Their Observational Universalities”
    JSPS Research Fellow for Young Scientists (DC2, during enrollment)
    Current position: ZJU100 Young Professor at Zhejiang University, China
  • Yohei Miki
    PhD in Science, March 2014, and Master of Engineering, March 2013, through the Dual Degree Program
    Doctoral dissertation: “Numerical Investigation of Galactic Mergers Utilizing High-Performance Computing Architectures: Ancient Satellite Galaxies and Wandering Supermassive Black Holes”
    Current position: Associate Professor at the University of Tokyo

Graduates (Master's degree)

  • Taisei Takeuchi
    Master’s degree (March 2026)
    Galaxy Interactions and Evolution in the M81 Group
    Employment in an enterprise
  • Kotaro Hiraki (Degree Program in Education)
    Master’s degree (March 2026)
    Intuitive Understanding of Physical Phenomena through the Visualization of Numerical Simulations and Its Educational Applications for Students
    High school teacher
  • Misa Yamaguchi
    Master’s degree (March 2025)
    "Formation of the Andromeda Giant Southern Stream and the Eastern Extent"
    Ph.D. student
  • Kazuma Koyata
    Master’s degree (March 2024)
    "Hydrodynamic interactions between dwarf galaxies and galactic disks"
    Employment in an enterprise
  • Yuka Kaneda
    Master’s degree (March 2023)
    "Scaling Laws and Cusp-Core Transitions in Dark Matter Haloes"
    Ph.D. student
  • Shunji Tanaka
    Master’s degree (March 2023)
    "Construction of an analytical model and numerical experiments with N-body simulations in the tidal stripping of satellite galaxies"
    Employment in an enterprise
  • Ayami Hotta
    Master’s degree (March 2023)
    "The dynamical evolution of the Andromeda Galaxy and the formation of stellar streams"
    Employment in an enterprise
  • Yudai Kazuno
    Master’s degree (March 2022)
    "Frequency of dark matter sub-halo collisions and their evolution"
    High school teacher
  • Koki Otaki
    Master’s degree (March 2021)
    "Formation of dark matter deficient galaxies via dark matter sub-halo collisions"
    Ph.D. student
  • Ryuji Sasaki
    Master’s degree (March 2020)
    "Evolution of Milky Way disk explored by galaxy collision simulations"
    Employment in an enterprise
  • Yuta Nagano
    Master’s degree (March 2019)
    "Possible existence of transonic and subsonic flows in galactic winds"
    Japan Meteorological Agency
  • Ginjiro Miyagawa
    Master’s degree (March 2019)
    "Possible existence of dark satellites explored by simulation of the formation of HI gas streams associated with IC10"
  • Moemi Tanuma
    Master’s degree (March 2018)
    "Universal scaling law for dark matter halo"
    Employment in an enterprise
  • Takahiro Fujiwara
    Master’s degree (March 2018)
    "Development of a new Godunov SPH method using the Integral Approach"
    Employment in an enterprise
  • Naohisa Kusu
    Master’s degree (March 2017)
    "Exploring the structure of the outer edge of the Andromeda Galaxy's dark matter halo and collisional orbits explored by galaxy collision simulations"
    Employment in an enterprise
  • Shohei Shibano
    Master’s degree (March 2017)
    "Interactions between interstellar gas and stellar winds in the galactic evolution of M31"
    Employment in an enterprise
  • Fumika Yuki
    Master’s degree (March 2016)
    "Simulation of the formation of nuclei in dwarf elliptical galaxies"
    Employment in an enterprise
  • Kazuki Kato
    Master’s degree (March 2015)
    "Relationship between the cusp-core problem and the too-big-to-fail problem in the Cold dark matter halo"
    Ph.D. student
  • Takanori Murata
    Master’s degree (March 2015)
    "Outflow and galaxy shape in the early stages of galaxy formation"
    Employment in an enterprise
  • Takanobu Kirihara
    Master’s degree (March 2014)
    "Internal structure of galaxies and dark matter halos probed by dwarf galaxy collisions"
    Ph.D. student
  • Asuka Igarashi
    Master’s degree (March 2013)
    "Analysis of spherically symmetric stationary galactic winds"
    Ph.D. student
  • Masami Tsuchiya
    Master’s degree (March 2012)
    "Transonic solutions of spherically symmetric stationary galactic winds - in relation to the mass density distribution of galaxies"
    Employment in an enterprise
  • Go Ogiya
    Master’s degree (March 2011)
    "Effects of gravitational field variations due to gas heating in supernova explosions on the central density distribution of the dark matter halo"
    Ph.D. student
  • Shigeyuki Nakamura
    Master’s degree (March 2011)
    "The relationship between galactic winds and a morphology of dwarf galaxies"
    Employment in an enterprise
  • Yohei Miki
    Master’s degree (March 2011)
    "Theoretical study of galaxy evolution and its impact on active galactic nuclei due to galaxy collisions"
    Ph.D. student