Biography

Zhao Zhang is currently a Ph.D. candidate in Astrophysics at Osaka University, working in the Department of Earth and Space Science under the supervision of Prof. Kentaro Nagamine. His research focuses on Fast Radio Bursts (FRBs), cosmology, and the distribution of baryonic matter in the Universe. In particular, he studies how FRB dispersion measures (DMs) can be used as probes of baryons across multiple spatial scales, from large-scale cosmic structures to local source environments.

His doctoral research mainly involves cosmological hydrodynamic simulations, especially the CROCODILE simulation, to investigate the baryon distribution in the cosmic web and the impact of AGN feedback on large-scale structures. By constructing FRB light-cone realizations through simulated volumes, he studies the statistical properties of FRB DMs and their dependence on redshift, environment, foreground halos, and host galaxies. These studies aim to provide a self-consistent framework for understanding FRBs as cosmological probes and for addressing the long-standing missing baryon problem.

In addition to cosmological studies, he also works on modeling FRB source environments using hydrodynamic simulations of supernova remnants (SNRs). His recent work focuses on the time evolution of local DM and free-free absorption around young magnetars, with the goal of understanding how source environments affect the observability of FRBs and their cosmological applications.

Before joining Osaka University, he received his M.S. degree in Astrophysics from Nanjing University, where he worked on high-energy astrophysical transients including magnetar giant flares, gamma-ray bursts (GRBs), and related radiation mechanisms. He obtained his B.S. degree in Physics from Guangxi University, where he studied the spectral properties of GRBs.

Research interest

Fast Radio Bursts and Cosmology

FRB dispersion measures as probes of cosmic baryon distribution;
FRB cosmology and the missing baryon problem;
Statistical studies of FRB DMs using cosmological hydrodynamic simulations;
FRB source environments and local propagation effects.

Cosmological Hydrodynamical Simulations

Baryon distribution in the cosmic web, intergalactic medium, and galactic halos;
AGN feedback and its impact on large-scale structures;
Light-cone construction and line-of-sight analysis through simulated cosmic volumes.

High-Energy Astrophysics

Magnetar giant flares and their radiation mechanisms;
Gamma-ray bursts and spectral analysis;
Supernova remnants, young magnetars, and FRB local environments.

Publications

Probing the Dispersion and Rotation Measure Contributions from Supernova Remnants in Fast Radio Burst Source Environments with 1D SNR Simulation
Zhao Joseph Zhang, Gaku Kawashima, Shiu-Hang Lee, Kentaro Nagamine, Bing Zhang, and Yusei Fujimaru.
Submitted (2026)

Probing the cosmic baryon distribution and the impact of AGN feedback with FRBs in CROCODILE simulation
Zhao Joseph Zhang, Kentaro Nagamine, Oku Yuri, et al.
Astrophysical Journal 993, 162 (2025)

Comptonized Fireball Bubble: Physical Origin of Magnetar Giant Flares
Zhao Joseph Zhang, Bin-Bin Zhang, Yan-Zhi Meng.
Monthly Notices of the Royal Astronomical Society 520, 6195 (2023)

A First-Principles Formulation of High-Energy Radiation from Magnetar Giant Flares
Umer Rehman, Zhao Joseph Zhang, Bin-Bin Zhang.
Journal of High Energy Astrophysics 50, 100489 (2026)

A Comptonized Fireball Bubble Fits the Second Extragalactic Magnetar Giant Flare GRB 231115A
Yi-Han Iris Yin, Zhao Joseph Zhang, et al.
Astrophysical Journal Letters 961, L10 (2024)

A Comprehensive Consistency Check between Synchrotron Radiation and the Observed Gamma-Ray Burst Spectra
Dao-Zhou Wang, Xiao-Hong Zhao, Zhao Zhang, Bin-Bin Zhang, Zhao-Yang Peng.
Astrophysical Journal (2021)

GRB 140102A: Insight into Prompt Spectral Evolution and Early Optical Afterglow Emission
Rahul Gupta, S. R. Oates, S. B. Pandey, A. J. Castro-Tirado, Jagdish C. Joshi, Y.-D. Hu, A. F. Valeev, B. B. Zhang, Zhao Zhang and collaborators.
Monthly Notices of the Royal Astronomical Society 505, 4086 (2021)

Evidence for gravitational lensing of GRB 200716C
Xing Yang, Hou-Jun Lü, Hao-Yu Yuan, Zhao Zhang, Bin-Bin Zhang, and En-Wei Liang.
Astrophysical Journal Letters (2021)

Contact

Address: Department of Earth and Space Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.

Email: zzhang@astro-osaka.jp

Email (personal): zhangzhao981013@outlook.com