collaborators

10 papers

astro-ph.HE2025

J-GEM near-infrared follow-up observations of the gravitational wave event S240422ed

Ichiro Takahashi, Tomoki Morokuma, Masaomi Tanaka +9

We report our near-infrared (NIR) follow-up observations of the gravitational wave (GW) event S240422ed using the Subaru Telescope/MOIRCS. S240422ed was initially classified as a b…

astro-ph.HE2025

Neutrino pair annihilation driven jets from black-hole torus systems

Kyohei Kawaguchi, Sho Fujibayashi, Masaru Shibata

We perform axisymmetric general relativistic radiation-viscous hydrodynamics simulations of black hole (BH)-torus systems with full Boltzmann Monte-Carlo neutrino transport to inve…

astro-ph.HE2025

Signatures of Exploding Supermassive PopIII Stars at High Redshift in JWST, EUCLID and Roman Space Telescope

Cédric Jockel, Kyohei Kawaguchi, Sho Fujibayashi +1

Recently discovered supermassive black holes with masses of at redshifts - in active galactic nuclei (AGN) pose severe challenges to our understandi…

astro-ph.HE2025

Collapse of Rotating White Dwarfs and Multimessenger Signals

Takami Kuroda, Kyohei Kawaguchi, Masaru Shibata

We present results of numerical relativity simulations for the collapse of rotating magnetized white dwarfs (WDs) in three dimension, aiming at discussing the explosion dynamics an…

astro-ph.HE2025

Black hole-accretion disk collision in general relativity: Axisymmetric simulations

Alan Tsz-Lok Lam, Masaru Shibata, Kyohei Kawaguchi +1

Motivated by recent discoveries of X-ray quasi-periodic eruptions, we revisit the collision of a black hole and an accretion disk. Assuming that they are orbiting a supermassive bl…

astro-ph.HE2025

Viscous accretion and ejection from tori around black holes in general relativity

Masaru Shibata, Kyohei Kawaguchi, Alan Tsz-Lok Lam

We systematically perform long-term (millions of Schwarzschild time) axisymmetric viscous hydrodynamics simulations for tori around black holes in general relativity supposing the…