A5074638212- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Radio Astronomy Observations and Technology
- Dark Matter and Cosmic Phenomena
- Neutrino Physics Research
- Particle Detector Development and Performance
- Astrophysical Phenomena and Observations
- Particle Accelerators and Free-Electron Lasers
- Pulsars and Gravitational Waves Research
- Radiation Detection and Scintillator Technologies
- Particle physics theoretical and experimental studies
- Nuclear Physics and Applications
- Astronomical Observations and Instrumentation
- Cosmology and Gravitation Theories
- Advanced X-ray and CT Imaging
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Gyrotron and Vacuum Electronics Research
- Adaptive optics and wavefront sensing
- Calibration and Measurement Techniques
- Galaxies: Formation, Evolution, Phenomena
- Radiation Therapy and Dosimetry
- Peripheral Nerve Disorders
- Precipitation Measurement and Analysis
- Photocathodes and Microchannel Plates
Obayashi (Japan)
2022-2024
Nagoya University
2022-2024
Universitat de Barcelona
2021-2024
Institut d'Estudis Espacials de Catalunya
2024
The University of Tokyo
2014-2023
Kavli Institute for the Physics and Mathematics of the Universe
2023
Tokai University
1990-2023
Czech Academy of Sciences, Institute of Physics
2023
Max Planck Institute for Physics
2020-2023
Czech Academy of Sciences
2023
Photomultiplier tubes (PMTs) have been widely used in imaging atmospheric Cherenkov telescopes (IACTs). The Large-Sized Telescopes (LSTs) of the Telescope Array Observatory (CTAO), latest-generation IACTs, are optimized for challenging observations low-energy gamma rays, specifically 20 to 150 GeV range. To this end, PMTs with an exceptionally low afterpulsing probability developed and installed. However, rate increases over time due infiltration molecules, particularly helium, into tube....
A 2.1-year periodic oscillation of the gamma-ray flux from blazar PG 1553+113 has previously been tentatively identified in almost 7 year data Fermi Large Area Telescope. After 15 years sky-survey observations, doubling total time range, we report >7 cycle modulation with an estimated significance 4 sigma against stochastic red noise. Independent determinations period and phase earlier new are close agreement (chance probability <0.01). Pulse timing over full light curve is also consistent a...
Mobile code is an emerging paradigm of distributed computing. It roams over a network, linked with application, and runs as part application. In the case Web browsers, it commonplace to download mobile code, called plug-in, from truly open network such Internet. Owing anonymity may be malicious; thus, important protect local computing resources attacks by malicious code. We have developed kernel that supports fine-grained protection domains preclude making unauthorized accesses resources....
The IceCube neutrino observatory is a 1 km$^3$ detector deployed in the ice at South Pole. While it has observed an astrophysical flux of neutrinos, individual sources have yet to be identified and high-peaked BL Lac object 1ES 1959+650 intriguing candidate. It exhibited ``orphan flare'' 2002: TeV gamma ray flare without simultaneous X-ray flare, behavior that hard accommodate leptonic synchrotron self-compton models. This suggests potential site hadronic acceleration thus prime source...
The Cherenkov Telescope Array (CTA) is the next-generation ground-based very-high-energy gamma-ray observatory. Large-Sized (LST) of CTA designed to detect gamma rays between 20 GeV and a few TeV with 23-meter diameter mirror. We have developed focal plane camera first LST, which has 1855 photomultiplier tubes (PMTs) readout system samples PMT waveform at GHz switched capacitor arrays, Domino Ring Sampler ver4 (DRS4). To measure precise pulse charge arrival time signals, we method calibrate...
The afterglow emission of gamma-ray bursts (GRBs) is basically well described by synchrotron radiation from fluid shocked collisions between the jets and external medium. However, several photons with energy tens GeV up to 94.1 have been detected \textit{Fermi} Large Area Telescope. Such challenging for shocks may require another component such as inverse-Compton scattering. Identifying responsible process in this range important revealing central engine dissipation which causes bursts. In...
Photo Multiplier Tubes (PMT) are the most wide-spread detectors for measuring fast, faint light signals.About seven years ago we started an improvement program PMT candidates Cherenkov Telescope Array (CTA) project with companies Hamamatsu Photonics K.K. (Japan) and Electron Enterprises Ltd. (England).CTA is next major Imaging Atmospheric Telescopes array high energy gamma-ray astrophysics; about 100 telescopes of sizes 23m, 12m 4m in diameter will be built Northern Southern hemispheres.For...