This section highlights our latest research activities, including publications, conference
              presentations, media coverage, and collaborative projects. We also share updates on team events
              and extracurricular activities that strengthen connections and promote a healthy work–life
              balance within the group.
            
            
              - 
                Oct. 11, 2025
 Yuka Kaneda (3rd-yr Ph.D. student) has been selected for both the JSPS Postdoctoral Fellowship (PD) and
                the JSPS Overseas
                Research Fellowship for FY 2026. Congratulations!
- 
                Oct. 6-10, 2025
 At the IAU Symposium “The Hidden Beauty of the Galactic Outskirts” held in Córdoba, Spain,
                Yuka Kaneda (D3) delivered a presentation titled “Detecting dark matter subhaloes and
                wandering intermediate-mass black holes through parallel stellar streams.”
- 
                Oct. 6-7, 2025
 At the “17th Symposium on Discovery, Fusion, Creation of New Knowledge by Multidisciplinary
                Computational Sciences,” held at the Tsukuba International Congress Center,
                Mayuka Oda (M1) presented a poster on her research titled “Concentrations of Dark Matter
                Subhalos in Galaxy Clusters: Lognormal Distributions and a Revised Concentration-Mass
                Relation.”
- 
                Oct. 2, 2025
 Kotaro Hiraki (2nd-yr M.S. student) delivered his Master’s thesis midterm presentation in the
                Graduate Program in Education (AY 2025) and successfully passed. Congratulations!
- 
                Oct. 1, 2025
 Misa Yamaguchi (1st-yr Ph.D. student) has received a selection offer for the JSPS Research Fellowship
                (DC2) for FY 2026. Congratulations!
- 
                Sep. 24, 2025
 I participated in the 2nd ARIHHP Salon and the 4th Cross-Departmental Academic Salon of the
                College of Systems and Information Engineering, “Toward deeper integration of health and
                sports science with computational science,” and presented a flash talk titled “Fluid dynamics
                linking athletes and black holes through computational science.”
- 
                Sep. 16–18, 2025
 I held a collaboration meeting at the University of Tsukuba with Assistant Professor
                Sakurako Okamoto (Subaru Telescope, NAOJ) and Taisei Takeuchi (2nd-year M.S. student) on the
                evolution of the M81 galaxy group.
- 
                Sep. 7–13, 2025
 I attended the international conference “COSMOLOGY 2025 @ ELBA ISLAND” in Italy and
                delivered a summary talk on our work on the structure and evolution of dark matter halos.
                  The two photos on the left show the conference venue, Hotel Ermitage. The third photo features Paolo
                  Salucci (SISSA: Scuola Internazionale Superiore di Studi Avanzati), and the fourth photo features
                  Peter Berczik (National Academy of Sciences of Ukraine).
                 
- 
                Sep. 9, 2025
 Misa Yamaguchi (1st-year Ph.D. student) presented her latest results, “Formation history of
                substructures in the Andromeda halo probed by galaxy collision simulations,” at the Autumn Annual
                Meeting of
                the Astronomical Society of Japan (Yamaguchi).
- 
                Sep. 4, 2025
 Misa Yamaguchi (1st-year Ph.D.
                  student) gave a poster presentation at “Mirai no Hakase 2025,” held at Hitotsubashi Hall, Hitotsubashi
                  University.
- 
                Sep. 1–5, 2025
 I attended the international conference “The Dynamic Universe” at Kloster Seeon, Germany, and reported
                recent results on galaxy collisions and black hole activity.
                  The two photos on the left show Kloster Seeon, the conference venue. Founded in 994 in Bavaria,
                  Germany, the monastery sits on a small island in Lake Seeon.
                  In the third photo, on the left is Prof. Andreas Burkert (LMU Munich) and in the center is Prof.
                  Reinhard Genzel (Max Planck Institute for Extraterrestrial Physics).
                  During my time as a research fellow at the Max Planck Institute for Astronomy (MPIA), Prof. Burkert
                  was a generous mentor and we have remained close personally.
                  Prof. Genzel received the 2020 Nobel Prize in Physics for observational research on the Galactic
                  Center black hole.
                  In the fourth photo, the person standing on the left is my longtime friend, Prof. Gerhard Hensler
                  (Professor Emeritus, University of Vienna).
                 
- 
                Aug. 26, 2025
 We submitted a co-authored paper with Koki Otaki (University of Rome), Yohei Miki (University of Tokyo),
                and Daisuke Takahashi (University of Tsukuba), entitled “Accelerated Hermite Integrator for
                  Orbital Integration with OpenACC and MPI”, to the Journal of Supercomputing.
- 
                Aug. 18, 2025
 Misa Yamaguchi (1st yr Ph.D. student) presented her research (in Japanese) at the “Science
                Expo: Connecting Myself and the Future,” held as part of Expo 2025 Osaka, Kansai.
                Her talk focused on large-scale simulations of galaxy collisions, particularly a minor merger in the
                Andromeda Galaxy, through which she explained the complex composite structure of stellar streams and its
                role in understanding galaxy formation.
- 
                
              
- 
                Aug. 13, 2025
 Additional information on computational science has been included on the Research
                  page.
- 
                Aug. 1, 2025
 As of August 1, I have taken on an additional role as an affiliated faculty member in the Computational Sport Science Division at
                    the Advanced Research Initiative for Human High Performance (ARIHHP), University of
                  Tsukuba.
                In parallel with my primary research in astrophysics, I will apply my expertise in fluid
                dynamics and computational science to the field of sports science, aiming to understand the
                distinctive dynamics of various athletic disciplines from a physics-based perspective.
- 
                Jul. 30, 2025
 We submitted a co-authored paper with Dr. Kohei Hayashi (Sendai National College of Technology),
                Yuka Kaneda (3rd-yr Ph.D. student), and Michi Shinozaki (1st-yr master's student),
                titled
                Cusp-to-Core Transition of Dark Matter Halos across Galaxy Mass Scales [arXiv:2507.22155] to PASJ.
- 
                Jul. 26, 2025
 We submitted a co-authored paper with Dr. Koki Otaki (postdoctoral researcher at the University
                of Rome) and Yudai Kazuno (graduated in 2022), titled
                Collision frequency between dark matter subhaloes within Milky Way-like
                  galaxies to the New Astronomy.
- 
                Jul. 17, 2025
 We had a kickoff meeting with Assistant Professor Hashimoto, a member of the observational group at the
                University of Tsukuba, to launch a new collaborative study.
                The goal of the project is to validate theoretical predictions about the nature of dark matter through
                new
                observations and joint analysis.
- 
                Jul. 11, 2025
 As part of the Undergraduate Research Experience Seminar, students visited the PEGASUS
                supercomputer, located in the annex of the Center for Computational Sciences at the University of
                Tsukuba.
                PEGASUS consists of 150 compute nodes equipped with GPU accelerators, each achieving a
                theoretical peak performance of 51 teraflops in double-precision floating-point operations. The system’s
                total theoretical peak performance reaches 8.1 petaflops.
                In our simulations of galaxy mergers, self-gravity calculations are accelerated using GPUs to enhance
                computational efficiency.
- 
                Jul. 2, 2025
 Akifumi Takayama, a first-year master’s student,
                presented his study “Galaxy Collisions and Activity of Supermassive
                Black Holes” at the 8th Supermassive Black Hole Research Promotion Meeting
                held at the University of Tsukuba.
- 
                Jun. 24, 2025
 Yuka Kaneda, a third-year Ph.D. student, visited Prof. Andrea Ferrara at Scuola Normale Superiore in
                Pisa,
                Italy, where she presented a seminar on our latest research findings.
- 
                Jun. 23, 2025
 A joint research meeting was held at the University of Tokyo's Kashiwa Campus with Yohei Miki, Misa
                Yamaguchi (1st-yr, Ph.D. student), Akifumi Takayama (1st-yr, Master's student), and Yoshitomo Takahashi
                (1st-yr, Master's student). Following the meeting, we visited the
                supercomputer MIYABI, a collaborative development by the University of Tsukuba and the
                University of Tokyo.
 
 MIYABI recorded 46.80 PFLOPS on the TOP500 supercomputer performance ranking, making it
                the second-fastest
                research system in Japan, following RIKEN’s Fugaku. It plays a crucial role in our group’s
                investigations
                of galaxy evolution, black hole activity, and dark matter halos.
- 
                Jun. 22, 2025
 As a recreational event, we enjoyed a sport climbing session for the first time in a while. With the
                participation of new members, it was a wonderful opportunity to strengthen ties not only within our team
                but also with colleagues from the broader theoretical astrophysics group.
                
                A total of 11 members joined — six with prior experience and five trying it for the first time. In a
                friendly and supportive atmosphere, we challenged both bouldering and top-rope routes. Arriving at the
                climbing gym around noon, we ended up staying past 7 p.m., fully absorbed in the experience.
- 
                Jun. 16–20, 2025
 Yuka Kaneda (3rd-yr, Ph.D. student) delivered a presentation on our research findings at the
                international
                conference “Dancing in the Dark: When Galaxies Shape Galaxies,” held in Sexten, Italy.
- 
                May 31–Jun. 4, 2025
 We visited Zhejiang University (Hangzhou, China) to conduct collaborative research discussions with Dr
                Go
                Ogiya (Ph.D. 2014), focusing on recent progress and future plans.
                  The visit to Zhejiang University—surrounded by natural beauty and an expansive campus—was a highly
                  valuable and stimulating experience. Dr. Go Ogiya, our first doctoral graduate, is currently serving
                  as
                  a tenure-track professor at the university. A highlight of the visit was the engaging research
                  presentations and discussions with his graduate students, Junnan Shen and Zhihao Yin (2nd-yr, Master's
                  student).
                 
- 
                May 30, 2025
 Misa Yamaguchi (1st-yr, Ph.D. student) has been awarded a fellowship under the JST Next Generation
                Researcher Challenging Research Program (SPRING). She will receive financial support for both her
                research
                and living expenses.
                Congratulations!
- 
                May 26–30, 2025
 I participated in the international conference “Expanding the Boundaries of Dark Matter Halo,” held at
                Shanghai Jiao Tong University (Program), where
                recent results from our joint study with Michi Shinozaki (first year master’s student), Yuka Kaneda
                (third year Ph.D. student), and Kohei Hayashi (Sendai KOSEN), titled “Understanding the Cusp to Core Transition and
                the Characteristic Radius in Dark Matter Halos,” were presented.
- 
                May 26–30, 2025
 Yuka Kaneda (3rd-yr, Ph.D. student) delivered a presentation 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 Osaka University’s Nakanoshima Center.
- 
                May 24, 2025
 The paper titled “Simultaneous Formation of the Andromeda Giant Southern Stream and the Substructures in
                the Andromeda Halo,” co-authored by Misa Yamaguchi (1st-yr, Ph.D. student), Takanobu Kirihara (Kitami
                Institute of Technology), Yohei Miki (University of Tokyo), Itsuki Ogami (NAOJ), Masashi Chiba (Tohoku
                University),
                Yutaka Komiyama (Hosei University), and Mikito Tanaka (Hosei University), has been published in
                PASJ.
                [PASJ]
- 
                May 21, 2025
 The team grew to 13 members in 2025, and although a bit late, we finally had a welcome party to
                celebrate
                the new arrivals.
- 
                May 14–16, 2025
 At the “Bigdata Astronomy 2025” workshop held at the University of Tsukuba, Yuka Kaneda (3rd-yr, Ph.D.
                student) presented her work titled “Estimating Dark Matter Halo Density Profiles from Stellar Streams
                Using Convolutional Neural Networks” and Misa Yamaguchi (1st-yr, Ph.D. student) presented her research
                titled “Simultaneous Formation of the Four Substructures in the Andromeda Halo.”
- 
                May 12, 2025
 Our proposed project “Galaxy Collisions and the Evolution of the Galactic Habitable Zone” has been
                accepted as a 2025 NAOJ Astrobiology Center Project. All formal procedures have been completed.
- 
                May 11, 2025
 The annual joint BBQ of the theoretical and observational astrophysics groups at the University of
                Tsukuba
                was held at "Yukari-no-Mori."
- 
                May 1, 2025
 In 2025, I started a new challenge in sports science research. Building on our expertise in
                astrophysical
                fluid dynamics, I am exploring its potential applications to athletic performance and biomechanics.
- 
                Apr. 28, 2025
 One of our undergraduate thesis students has chosen to pursue research through analytical approaches
                rather than numerical simulations. While this path may not produce the visually striking figures often
                seen in simulation work, it offers a powerful way to understand complex cosmic phenomena by tracing them
                back to fundamental physical processes — and can lead to deeply meaningful insights.
- 
                Apr. 21, 2025
 All first-year students have now finalised their research topics. In our group, we emphasise thorough
                discussions to ensure that each topic is well-matched to the student’s interests and abilities.
- 
                Apr. 1, 2025
 With the beginning of the new academic year, we have welcomed the following individuals to our team: as
                first-year students in the Master’s Programme — Kanta Aimoto, Mayuka Oda, Michi Shinozaki,
                Yoshitomo Takahashi, and Akifumi Takayama; and as undergraduate thesis students — Maria Arima,
                Taisei Nomura, and Kenta Hagiwara.