A5102972939- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- SAS software applications and methods
- Pulsars and Gravitational Waves Research
- Astronomy and Astrophysical Research
- Geophysics and Gravity Measurements
- Solar and Space Plasma Dynamics
- Statistical and numerical algorithms
- Astrophysics and Cosmic Phenomena
- Stellar, planetary, and galactic studies
- Particle Detector Development and Performance
- Earthquake Detection and Analysis
- Mechanics and Biomechanics Studies
- Indian and Buddhist Studies
- Particle Accelerators and Free-Electron Lasers
- Magnetic confinement fusion research
- Astro and Planetary Science
- High-pressure geophysics and materials
- Atmospheric Ozone and Climate
- Nuclear Physics and Applications
- Advanced X-ray Imaging Techniques
- Astrophysics and Star Formation Studies
- Inertial Sensor and Navigation
- Environmental Sustainability in Business
Waseda University
2013-2024
Chuo University
2020-2022
RIKEN
2020-2021
Nippon Soken (Japan)
2021
Ehime University
2004
Tokyo Institute of Technology
1999
We report multi-wavelength monitoring observations of an M-dwarf flare star AD Leonis with Seimei Telescope (6150--7930 {\AA}), SCAT (Spectroscopic Chuo-university Astronomical Telescope; 3700--7500 NICER (Neutron Star Interior Composition Explorer; 0.2--12.0 keV), and collaborations OISTER (Optical Infrared Synergetic Telescopes for Education Research) program. Twelve flares are detected in total which include ten H$\alpha$, four X-ray, optical-continuum flares; one them is a superflare the...
This study investigates the impact of introducing corporate social responsibility (CSR) committees on firms' CSR performance. Using a sample publicly traded Japanese companies for period 2011–2021, we employ propensity score matching difference-in-differences methods to address endogeneity issues. Our main findings reveal that introduction committee significantly improves performance, providing support importance structured and dedicated efforts toward achieving sustainability. In addition,...
Abstract We report that the RS CVn–type star GT Mus (HR 4492, HD 101379+HD 101380) was most active in X-ray sky last decade terms of scale recurrent energetic flares. detected 11 flares from 8 yr observations with Monitor All-sky Image (MAXI) 2009 August to 2017 August. The flare peak luminosities were 1–4 × 10 33 erg s −1 2.0–20.0 keV band for its distance 109.6 pc. Our timing analysis showed long durations ( τ r + d ) 2–6 days decay times days. released energies during phases 0.1–100 range...
The Eu-doped GaN thin films (GaN:Eu) were deposited on the sapphire substrate by means of rf magnetron sputtering method. GaN:Eu characterized x-ray diffraction, scanning electron microscope, and photoluminescence (PL). Although as-grown (2mol% Eu in target) exhibited weak broad Eu-related red PL, annealing NH3 atmosphere (1000°C for 1h) led to remarkable enhancement PL lines. spectra such annealed a series sharp lines characteristic substitutional Eu3+ ions at Ga sites lattice (dominant...
We report on the results of our simultaneous observations three large stellar flares with soft X-rays (SXRs) and an H$\mathrm{\alpha}$ emission line from two binary systems RS CVn type. The energies released in X-ray emissions during were $10^{36}$--$10^{38}$ $10^{35}$--$10^{37}$ erg, respectively. It renders set as first successful X-ray/H$\mathrm{\alpha}$ above $10^{35}$ erg; although coverage was limited, $\sim$10\% $e$-folding time decay phase flares, that SXR ones complete. Combining...