144 citations · 422 across the 10 of their papers we have counts for
11 papers
Black-hole formation and thermalization in open JT gravity
Ryo Adachi, Rumi Hasegawa, Takanori Ishii +1
Black-hole formation is expected, via holography, to correspond to thermalization in the boundary theory. For open quantum systems, an initial pure state generically evolves into a…
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…
Discovery of a Long-Duration Superflare on a Young Solar-Type Star EK Draconis with Nearly Similar Time Evolution for H and White-Light Emissions
Kosuke Namekata, Hiroyuki Maehara, Satoshi Honda +17
Young solar-type stars are known to show frequent "superflares", which may severely influence the habitable worlds on young planets via intense radiations and coronal mass ejection…
Probable detection of an eruptive filament from a superflare on a solar-type star
Kosuke Namekata, Hiroyuki Maehara, Satoshi Honda +20
Solar flares are often accompanied by filament/prominence eruptions ( K and cm), sometimes leading to coronal mass ejections (CMEs) that direct…
J-GEM optical and near-infrared follow-up of gravitational wave events during LIGO's and Virgo's third observing run
Mahito Sasada, Yousuke Utsumi, Ryosuke Itoh +68
The Laser Interferometer Gravitational-wave Observatory Scientific Collaboration and Virgo Collaboration (LVC) sent out 56 gravitational-wave (GW) notices during the third observin…
Multi-wavelength photometry during the 2018 superoutburst of the WZ Sge-type dwarf nova EG Cancri
Mariko Kimura, Keisuke Isogai, Taichi Kato +45
We report on the multi-wavelength photometry of the 2018 superoutburst in EG Cnc. We have detected stage A superhumps and long-lasting late-stage superhumps via the optical photome…
GPU-accelerated Image Reduction Pipeline
Masafumi Niwano, Katsuhiro L. Murata, Ryo Adachi +6
We developed a high-speed image reduction pipeline using Graphics Processing Units (GPUs) as hardware accelerators. Astronomers desire detecting EM counterpart of gravitational-wav…
Optical and X-ray observations of stellar flares on an active M dwarf AD Leonis with Seimei Telescope, SCAT, NICER and OISTER
Kosuke Namekata, Hiroyuki Maehara, Ryo Sasaki +24
We report multi-wavelength monitoring observations of an M-dwarf flare star AD Leonis with Seimei Telescope (6150--7930 Å), SCAT (Spectroscopic Chuo-university Astronomical Telesco…
Type Ia SN 2019ein: New Insights into the Similarities and diversities among High-Velocity SNe Ia
Miho Kawabata, Keiichi Maeda, Masayuki Yamanaka +38
We present optical observations of type Ia supernova (SN) 2019ein, starting at 2 days after the estimated explosion date. The spectra and the light curves show that SN 2019ein belo…
X-ray and Optical Monitoring of State Transitions in MAXI J1820+070
Megumi Shidatsu, Satoshi Nakahira, Katsuhiro L. Murata +4
We report results from the X-ray and optical monitoring of the black hole candidate MAXI J1820+070 (=ASSASN-18ey) over the entire period of its outburst from March to October 2018.…
X-ray, Optical, and Near-infrared Monitoring of the New X-ray Transient MAXI J1820+070 in the Low/hard State
Megumi Shidatsu, Satoshi Nakahira, Satoshi Yamada +26
We report X-ray, optical, and near-infrared monitoring of the new X-ray transient MAXI J1820070 discovered with MAXI on 2018 March 11. Its X-ray intensity reached Crab…