8 papers
Resolving Nearby Supermassive Black Holes with the Black Hole Explorer
Yuto Akiyama, Kazunori Akiyama, Dominic W. Pesce +12
Recent Event Horizon Telescope results have demonstrated unique and transformative science in gravitational physics and black hole astrophysics enabled by event-horizon-scale imagi…
Radio Constraints on the Circumstellar Environment of the Type IIb Supernova SN 2024iss
Yuhei Iwata, Tomoki Matsuoka, Masanori Akimoto +6
Type~IIb supernovae exhibit diverse progenitor properties, and radio observations offer a unique probe of their mass-loss histories shortly before the explosion. We present Japanes…
Black Hole Explorer Mission Development in Japan
Kazunori Akiyama, Mareki Honma, Akihiro Doi +21
The Black Hole Explorer (BHEX) is a next-generation space very-long-baseline interferometry (VLBI) mission concept that will extend existing ground-based millimeter/submillimeter V…
VLBI Astrometry of Magnetars
Takuya Akahori, Sujin Eie, Kei Amada +8
The origin of the strongest magnetic fields in the Universe, i.e., the origin of magnetars, is a longstanding question. An enhanced dynamo effect in an irregular supernova explosio…
VLBI-Enabled Localization of Continuous GW Sources
Keitaro Takahashi, Takuya Akahori, Kenta Fujisawa +8
Pulsar timing arrays (PTAs) are opening the nanohertz gravitational-wave (GW) band by timing millisecond pulsars (MSPs) to target signals from supermassive black hole binaries (SMB…
Fast variability and circular polarization of the 6.7 GHz methanol maser in G33.6410.228
Kenta Fujisawa, Yui Sugiura, Yuta Kojima +5
The 6.7 GHz methanol maser in a high-mass star-forming region G33.6410.228 is known to exhibit burst-like flux variability due to an unknown mechanism. To investigate the burst…