activity
20242026
collaborators

6 papers

astro-ph.HE2026

Spectral and photometric variability of SS 433 observed with XRISM and simultaneous optical and near-infrared telescopes

Yusuke Sakai, Shinya Yamada, Yuta Okada +36

We present results from coordinated multiwavelength observations of the SS 433, obtained with XRISM, optical telescopes, and near-infrared camera during 2024 April and 2025 March.…

astro-ph.HE2025

Multiband Optical Photometric and Spectroscopic Monitoring of the 2024 Flare Event in Transition Blazar OP313

TianFang Zhang, Mitsuru Kokubo, Mamoru Doi +19

Blazars are active galactic nuclei known for their extreme variability, offering unique opportunities to study jet physics and high-energy emission mechanisms. In 2024, the Flat Sp…

astro-ph.HE2025

XRISM reveals a variable, multi-phase outflow-inflow structure during the X-ray obscured 2024 outburst of the black hole transient V4641 Sgr

Maxime Parra, Megumi Shidatsu, Ryota Tomaru +23

We report the results of a simultaneous X-ray and optical spectroscopy campaign on the Galactic black hole X-ray binary V4641 Sgr, carried out with XRISM and the Seimei telescope d…

astro-ph.HE2024

The possible long-term periodic variability of the extremely luminous quasar WISE J090924.01+000211.1

Takashi Horiuchi, Yoshiki Toba, Toru Misawa +11

The extremely luminous infrared galaxy (ELIRG), WISE J090924.01+000211.1 (hereafter; WISE J0909+0002, ) is an extraordinary object with a quasar aspect. This study performs…

astro-ph.HE2024

Evolution of Accretion Disk Structure of the Black Hole X-ray Binary MAXI J1820070 during the Rebrightening Phase

Tomohiro Yoshitake, Megumi Shidatsu, Yoshihiro Ueda +18

To understand the evolution of global accretion disk structure in the ``rebrightening'' phase of MAXI J1820070, we perform a comprehensive analysis of its near infrared/optical/…

astro-ph.HE2024

Multiwavelength Observations of the Black Hole X-ray Binary MAXI J1820070 in the Rebrightening Phase

Tomohiro Yoshitake, Megumi Shidatsu, Yoshihiro Ueda +14

We report the results of quasi-simultaneous multiwavelength (near-infrared, optical, UV, and X-ray) observations of the Galactic X-ray black hole binary MAXI J1820+070 performed in…