High-Energy Astrophysics Lab

From the extreme environments around black holes to the radiation environment on the lunar surface — we tackle the mysteries of the high-energy universe through theory and multi-messenger observations (X-rays, MeV gamma rays, radio, neutrinos, and gravitational waves).
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Credit: RIKEN

Research

From fundamental astrophysics to applied radiation science.

01 — FUNDAMENTAL

Fundamental Astrophysics

Uncovering the physics of the high-energy universe — black holes and MeV gamma rays — through theory and multi-messenger observations.

Black Hole Astrophysics

Magnetic field measurements of AGN coronae (ALMA, IXPE, XRISM), accretion physics, and extreme physics near the event horizon.

AGN coronae X-ray polarimetry ALMA +1 more
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High-Energy Astrophysics (MeV)

Pioneering MeV gamma-ray astronomy and multi-messenger studies with IceCube neutrinos.

GRAMS neutrinos blazars
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Explore fundamental research
02 — APPLIED

Applied High-Energy and Radiation Studies

Applying our expertise in high-energy astrophysics to real-world radiation challenges of the space age.

Lunar Radiation Environment

Understanding and forecasting the cosmic-ray and radiation environment on the lunar surface for the era of human lunar activity.

cosmic rays solar energetic particles Artemis
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Explore applied research

News

New research grant awarded

Awarded a JSPS Kakenhi Challenging Research (Exploratory) grant.

Paper on XRISM time-resolved Fe K-alpha spectroscopy of NGC 4395 accepted by ApJ (Kawamuro et al.)

Probing the variable inner disk of an AGN with XRISM, with signatures of Lense-Thirring precession.

arXiv

Paper led by PhD student Nobuyuki Sakai accepted by ApJ

Revisiting AGN disk winds as an origin of the cosmic gamma-ray and neutrino backgrounds.

arXiv

New preprint on neutrino production sites in blazar jets (Xue et al.)

Locating where high-energy neutrinos are produced in blazar jets.

arXiv

Our collaborative Antennae galaxies study featured on phys.org (Komugi et al.)

The hidden supermassive black hole candidate study was covered by international media.

phys.org arXiv
Recent Publications
  • Xue, R., Inoue, Y., Wang, Z., Liao, N., Xiong, D. (2026). Locating the Production Sites of High-Energy Neutrinos in Blazar Jets. arXiv e-prints, arXiv:2606.02024. ADS / arXiv / DOI
  • PLUS Science Team, Baba, S., Belli, S., Benotto, P., Delvecchio, I., et al. (2026). GREX-PLUS Science Book v2. arXiv e-prints, arXiv:2606.05237. ADS / arXiv / DOI
  • Sakai, N., Inoue, Y., Owen, E. R. (2026). Revisiting Disk Winds in Active Galactic Nuclei as an Origin of Cosmic Gamma-ray and Neutrino Backgrounds. arXiv e-prints, arXiv:2606.17490. ADS / arXiv / DOI
  • Kawamuro, T., Yamada, S., Noda, H., Inoue, Y., Ogawa, S., et al. (2026). XRISM Time-resolved Fe K$α$ Spectroscopy of NGC 4395: Time-variable Inner-disk Emission. arXiv e-prints, arXiv:2606.21180. ADS / arXiv / DOI
  • Komugi, S., Saito, T., Michiyama, T., Inoue, Y., Nakanishi, K., et al. (2026). An Active Galactic Nucleus in the Antennae Galaxies?. The Astrophysical Journal 1004, 126. ADS / arXiv / DOI

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Join Us

We are recruiting graduate students (MSc/PhD), postdocs, and undergraduates. Black holes, gamma rays, neutrinos, or the Moon — if any of these excites you, get in touch.
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