activity
20242026
collaborators

6 papers

astro-ph.IM2026

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…

astro-ph.HE2026

XRISM spectroscopy of a crowded Galactic center region -- I. Disentangling the sources in the field of view

Maxime Parra, Kai Matsunaga, Shifra Mandel +16

The Galactic center is a complex and crowded region hosting the supermassive black hole Sgr A*, numerous accreting compact objects, and diffuse X-ray emission. This paper presents…

astro-ph.GA2025

Origin of Radio Emission in Three Nearby Ultraluminous Infrared Galaxies with Signatures of Luminous Buried Active Galactic Nuclei

Takayuki J. Hayashi, Yoshiaki Hagiwara, Masatoshi Imanishi

We report multifrequency Very Long Baseline Array (VLBA) observations at 2.3 and 8.4GHz of three nearby ultraluminous infrared galaxies, identified via mid-infrared spectroscopic a…

astro-ph.IM2024

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.GA2024

VLBI Detection of an Active Radio Source Potentially Driving 100-kpc Scale Emission in the Ultraluminous Infrared Galaxy IRAS F010042237

Takayuki J. Hayashi, Yoshiaki Hagiwara, Masatoshi Imanishi

The nearby ultraluminous infrared galaxy (ULIRG) IRAS F010042237 exhibits 100-kpc scale continuum emission at radio wavelengths. The absence of extended X-ray emission in IRAS F…

astro-ph.HE2024

A Giant Metrewave Radio Telescope Survey of Radio-loud Broad Absorption Line Quasars

Takayuki J. Hayashi, Akihiro Doi, Hiroshi Nagai

A substantial fraction of quasars display broad absorption lines (BALs) in their rest-frame ultraviolet spectra. While the origin of BALs is thought to be related to the accretion…