activity
20222026
most citedThe Japanese Vision for the Black Hole Explorer Mission

5 citations · 11 across the 6 of their papers we have counts for

collaborators

6 papers

gr-qc2026

Ellis-Bronnikov Wormhole Shadows with Spherically Symmetric Accretion Flow

Mikiya M. Takahashi, Keisuke Nakashi

We investigate the observational differences between the Ellis--Bronnikov (EB) wormhole and the Schwarzschild black hole (BH) by performing general relativistic radiative transfer…

astro-ph.HE2025

Black Hole Spin Estimation with Time-variable Image of M87 During the Flaring State

Mikiya M. Takahashi, Tomohisa Kawashima, Ken Ohsuga

By investigating the time-variable 230 GHz images using ray-tracing general relativistic radiative transfer calculation, we propose a novel method for estimating the spin parameter…

astro-ph.HE2025

A Face-on Accretion Disk Geometry Revealed by Millimeter-wave Periodicity in Sgr A

Kazuki Yanagisawa, Tomoharu Oka, Ryo Ariyama +3

We analyzed 77 epochs of Atacama Large Millimeter/submillimeter Array (ALMA) archival data to investigate flux variability in Sagittarius A (Sgr A), the supermassive black…

astro-ph.IM2024★ 5 cited

The Japanese Vision for the Black Hole Explorer Mission

Kazunori Akiyama, Kotaro Niinuma, Kazuhiro Hada +43

The Black Hole Explorer (BHEX) is a next-generation space very long baseline interferometry (VLBI) mission concept that will extend the ground-based millimeter/submillimeter arrays…

astro-ph.HE2024★ 2 cited

A Relativistic Formula for the Multiple Scattering of Photons

Rohta Takahashi, Masayuki Umemura, Ken Ohsuga +6

We have discovered analytical expressions for the probability density function (PDF) of photons that are multiply scattered in relativistic flows, under the assumption of isotropic…

astro-ph.HE2022★ 4 cited

3D Photon Conserving Code for Time-dependent General Relativistic Radiative Transfer : CARTOON

Mikiya M. Takahashi, Ken Ohsuga, Rohta Takahashi +3

We develop the 3-dimensional general relativistic radiative transfer code: CARTOON (Calculation code of Authentic Radiative Transfer based On phOton Number conservation in curved s…