activity
20032026
most citedJ-GEM observations of an electromagnetic counterpart to the neutron star merger GW170817

206 citations · 1.2k across the 53 of their papers we have counts for

collaborators
Showing astro-ph.HEShow all

14 papers · 1 filter

astro-ph.HE2026★ 4 cited

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

Evolution of the inner accretion flow and the white-dwarf spin pulse during the 2023 outburst in GK Persei

Mariko Kimura, Takayuki Hayashi, Yuuki Wada +8

We present our X-ray and optical observations performed by NICER, NuSTAR, and Tomo-e Gozen during the 2023 outburst in the intermediate polar GK Persei. The X-ray spectrum consiste…

astro-ph.HE2024

Evolution of X-ray and optical rapid variability during the low/hard state in the 2018 outburst of MAXI J1820+070 = ASASSN-18ey

Mariko Kimura, Hitoshi Negoro, Shinya Yamada +3

We performed shot analyses of X-ray and optical sub-second flares observed during the low/hard state of the 2018 outburst in MAXI J1820070. Optical shots were less spread than X…

astro-ph.HE2024

Optical Variability of Blazars in the Tomo-e Gozen Northern Sky Transient Survey

TianFang Zhang, Mamoru Doi, Mitsuru Kokubo +14

We studied the optical variability of 241 BL Lacs and 83 flat-spectrum radio quasars (FSRQ) from the 4LAC catalog using data from the Tomo-e Gozen Northern Sky Transient Survey, wi…

astro-ph.HE2024

Intermediate-luminosity Type IIP SN 2021gmj: a low-energy explosion with signatures of circumstellar material

Yuta Murai, Masaomi Tanaka, Miho Kawabata +28

We present photometric, spectroscopic and polarimetric observations of the intermediate-luminosity Type IIP supernova (SN) 2021gmj from 1 to 386 days after the explosion. The peak…