Kazuki Tomaru

Ph.D. Student in Astrophysics
Galaxy formation and evolution through cosmological simulations
Email: tomaru [at] astro-osaka.jp

Research interests: galaxy formation and evolution, cosmological hydrodynamic simulations, baryon cycle, internal dynamics and kinematics of galaxies

I am Kazuki Tomaru (Japanese: 戸丸 一樹), a Ph.D. student in the Theoretical Astrophysics (OUTAP) Group, Department of Earth and Space Science, Graduate School of Science, The University of Osaka, Japan, working under the supervision of Prof. Kentaro Nagamine.

My research focuses on galaxy formation and evolution in a cosmological context. I aim to understand how the diverse properties of galaxies emerge from the coupling between structure formation and baryonic processes across a wide range of scales. To this end, I use cosmological zoom-in hydrodynamic simulations, which self-consistently capture this multi-scale interplay. What fascinates me most is the rich complexity of baryonic physics.

Dwarf galaxies serve as both the building blocks of larger structures in hierarchical formation and extreme environments in which shallow gravitational potentials give rise to a complex interplay of the physical processes governing galaxy formation. My current focus is on their morphology and kinematics, which exhibit significant diversity linked to assembly history and baryonic processes. Recent observational advances are beginning to probe this regime statistically.

Research Activities

CROCODILE-DWARF: Cosmological Zoom-in Hydrodynamic Simulations of Dwarf Galaxies

I conduct cosmological zoom-in hydrodynamic simulations of dwarf galaxies using the GADGET4-OSAKA code. My work focuses on the morphological and kinematic diversity of gas and stars in dwarf galaxies, probing the galaxy–halo connection at the low-mass end.

Publications

Lead Author Publications

1. Tomaru, K., et al. 2025, CROCODILE-DWARF: Assembly and Kinematics of Field Dwarf Galaxies with GADGET4-OSAKA, ApJ, in press, arXiv:2510.26513 [SciX, ADS]

Contributing Author Publications

1. Zhang, Z. J., et al. (Tomaru, K. as 6th author) 2025, Probing the Cosmic Baryon Distribution and the Impact of Active Galactic Nuclei Feedback with Fast Radio Bursts in CROCODILE Simulation, ApJ, 993, 162 [SciX, ADS, arXiv]

Contact

If you'd like to get in touch, please do! You can reach me at tomaru [at] astro-osaka.jp.
Thank you for visiting my website!

Pronouns: he/him

Languages: Japanese (native), English

0009-0007-4378-406X