A5068543698- Astrophysics and Cosmic Phenomena
- Dark Matter and Cosmic Phenomena
- Neutrino Physics Research
- Particle Detector Development and Performance
- Radio Astronomy Observations and Technology
- Solar and Space Plasma Dynamics
- Particle physics theoretical and experimental studies
- Gamma-ray bursts and supernovae
- Particle Accelerators and Free-Electron Lasers
- Radiation Therapy and Dosimetry
- Ionosphere and magnetosphere dynamics
- Lightning and Electromagnetic Phenomena
- Radiation Detection and Scintillator Technologies
- Earthquake Detection and Analysis
- High-Energy Particle Collisions Research
- Pulsars and Gravitational Waves Research
- Astrophysical Phenomena and Observations
- Extracellular vesicles in disease
- Atmospheric Ozone and Climate
- Solar Radiation and Photovoltaics
- Meteorological Phenomena and Simulations
- Astrophysics and Star Formation Studies
- Knee injuries and reconstruction techniques
- Tendon Structure and Treatment
- Radioactivity and Radon Measurements
Boston University
2025
The University of Tokyo
2015-2024
Institute for Cosmic Ray Research
2021-2024
Hiroshima City University
2024
Ulsan National Institute of Science and Technology
2024
Osaka Metropolitan University
2023
RIKEN
2023
Osaka University
2023
University of California, Santa Cruz
2023
Furukawa Electric (United Kingdom)
2022
We have searched for intermediate-scale anisotropy in the arrival directions of ultrahigh-energy cosmic rays with energies above 57~EeV northern sky using data collected over a 5 year period by surface detector Telescope Array experiment. report on cluster events that we call hotspot, found oversampling 20$^\circ$-radius circles. The hotspot has Li-Ma statistical significance 5.1$\sigma$, and is centered at R.A.=146.7$^{\circ}$, Dec.=43.2$^{\circ}$. position about 19$^{\circ}$ off...
We report, for the first time, long-awaited detection of diffuse gamma rays with energies between 100 TeV and 1 PeV in Galactic disk. Particularly, all above 398 are observed apart from known gamma-ray sources compatible expectations hadronic emission scenario which originate decay $π^0$'s produced through interaction protons interstellar medium Galaxy. This is strong evidence that cosmic accelerated beyond our Galaxy spread over
The intensity of Galactic cosmic rays is nearly isotropic because the influence magnetic fields in Milky Way. Here, we present two-dimensional high-precision anisotropy measurement for energies from a few to several hundred teraelectronvolts (TeV), using large data sample Tibet Air Shower Arrays. Besides revealing finer details known anisotropies, new component ray sidereal time uncovered around Cygnus region direction. For cosmic-ray up TeV, all components anisotropies fade away, showing...
We present an updated all-particle energy spectrum of primary cosmic rays in a wide range from 1014 to 1017 eV using 5.5 × 107 events collected 2000 November through 2004 October by the Tibet-III air-shower array located 4300 m above sea level (an atmospheric depth 606 g cm−2). The size exhibits sharp knee at corresponding around 4 PeV. This work uses increased statistics and new simulation calculations for analysis. discuss our extensive Monte Carlo model dependencies involved final result,...
The Telescope Array observatory utilizes fluorescence detectors and surface to observe air showers produced by ultra high energy cosmic rays in the Earth's atmosphere. Cosmic ray events observed this way are termed hybrid data. depth of shower maximum is related mass primary particle that generates shower. This paper reports on maxima data collected over 8.5 years using Black Rock Mesa Long Ridge conjunction with array detectors. We compare means standard deviations $X_{\mathrm{max}}$...
We report on a measurement of the cosmic ray energy spectrum by Telescope Array Low-Energy Extension (TALE) air fluorescence detector. The TALE detector is also sensitive to Cherenkov light produced shower particles. Low rays, in PeV range, are detectable as "Cherenkov Events". Using these events, we measure from low $\sim 2$ an greater than 100 PeV. Above can detect rays using fluorescence. This allows for extension energies few EeV. In this paper, will describe detector, explain technique,...
Cosmic rays are energetic charged particles from extraterrestrial sources, with the highest-energy events thought to come extragalactic sources. Their arrival is infrequent, so detection requires instruments large collecting areas. In this work, we report of an extremely particle recorded by surface detector array Telescope Array experiment. We calculate particle's energy as [Formula: see text] (~40 joules). Its direction points back a void in large-scale structure Universe. Possible...
We present the large-scale sidereal anisotropy ofgalactic cosmic-ray intensity in multi-TeV region observed with Tibet-IIIair shower array during period from 1999 through 2003. The daily variation of cosmic rays this experiment shows an excess relative around $4\sim7 $ hours local time, as well a deficit 12 time. While amplitude is not significant when averaged over all declinations, individual declinaton bands becomes larger and clearer viewing direction moves toward south. maximum phase...
During the 2010 rainy season in Yangbajing (4300 m above sea level) Tibet, China, a long-duration count enhancement associated with thunderclouds was detected by solar neutron telescope and monitors installed at Comic Ray Observatory. The event, lasting for $\sim$40 min, observed on July 22, 2010. significant $\gamma$-ray signals energies $>$40 MeV event. Such prolonged high-energy event has never been association thunderclouds, clearly suggesting that electron acceleration lasts 40 min...
Abstract Bursts of gamma ray showers have been observed in coincidence with downward propagating negative leaders lightning flashes by the Telescope Array Surface Detector (TASD). The TASD is a 700‐km 2 cosmic observatory located southwestern Utah, USA. In data collected between 2014 and 2016, correlated observations showing structure temporal development three shower‐producing were obtained 3‐D mapping array, electric field change measurements for an additional seven flashes, both cases...
Abstract We report on the analysis of 10–1000 TeV large-scale sidereal anisotropy Galactic cosmic rays (GCRs) with data collected by Tibet Air Shower Array from 1995 October to 2010 February. In this analysis, we improve energy estimate and extend decl. range down −30°. find that maps above 100 are distinct at a multi-TeV band. The so-called tail-in loss-cone features identified low energies get less significant, new component appears ∼100 TeV. spatial distribution GCR intensity an excess...
One of the uncertainties in interpretation ultrahigh energy cosmic ray data comes from hadronic interaction models used for air shower Monte Carlo (MC) simulations. The number muons observed at ground ray--induced showers is expected to depend upon model. may therefore test by comparing measured with MC prediction. In this paper, we present results studies muon densities extensive obtained analyzing signal surface detector stations which should have high purity. purity a station will on both...
In this paper we report the first close, high-resolution observations of downward-directed terrestrial gamma-ray flashes (TGFs) detected by large-area Telescope Array cosmic ray observatory, obtained in conjunction with broadband VHF interferometer and fast electric field change measurements parent discharge. The results show that TGFs occur during strong initial breakdown pulses (IBPs) few milliseconds negative cloud-to-ground low-altitude intracloud flashes, IBPs are produced a...
We report on a measurement of the cosmic ray composition by Telescope Array Low-Energy Extension (TALE) air fluorescence detector (FD). By making use Cherenkov light signal in addition to from (CR) induced extensive showers, TALE FD can measure properties rays with energies as low $\sim 2$ PeV and exceeding 1 EeV. In this paper, we present results $X_{\rm max}$ distributions showers observed over energy range. Data collected period 4$ years was analyzed for study. The resulting are compared...
The Tibet-III air shower array, consisting of 533 scintillation detectors, has been operating successfully at Yangbajing in Tibet, China since 1999. Using the data set collected by this array from 1999 November through 2005 November, we obtained energy spectrum γ-rays Crab Nebula, expressed a power law as (dJ/dE) = (2.09 ± 0.32) × 10−12(E/3 TeV)−2.96±0.14 cm−2 s−1 TeV−1 range 1.7–40 TeV. This result is consistent with other independent γ-ray observations imaging Cherenkov telescopes. In...
We report on a clear solar-cycle variation of the Sun's shadow in 10 TeV cosmic-ray flux observed by Tibet air shower array during full solar cycle from 1996 to 2009. In order clarify physical implications variation, we develop numerical simulations shadow, using potential field source surface model and current sheet (CSSS) for coronal magnetic field. find that intensity deficit simulated is very sensitive structure, better reproduced CSSS model. This first successful attempt evaluate models flux.
We search for correlations between positions of extragalactic objects and arrival directions Ultra-High Energy Cosmic Rays (UHECRs) with primary energy $E \ge 40$ EeV as observed by the surface detector array Telescope Array (TA) experiment during first 40 months operation. examined several public astronomical object catalogs, including Veron-Cetty Veron catalog active galactic nuclei. counted number TA events correlated in each a function three parameters: maximum angular separation event...
In this work we are reporting on the measurement of proton-air inelastic cross section $\sigma^{\rm inel}_{\rm p-air}$ using Telescope Array (TA) detector. Based proton-proton $\sigma_{\rm p-p}$ value is also determined at $\sqrt{s} = 95_{-8}^{+5}$ TeV. Detecting cosmic ray events ultra high energies with enables us to study fundamental parameter that otherwise unable access particle accelerators. The data used in report hybrid observed by Middle Drum fluorescence detector together surface...
Results on steady TeV $\gamma$-ray point source search using data taken from the Tibet HD (Feb. 1997 -- Sep. 1999) and III (Nov. 1999 Oct. 2001) arrays are presented. From $0^{\circ}$ to $60^{\circ}$ in declination, significant excesses well-known Crab Nebula high state of flare type Markarian 421 observed. Because levels significance other positions not sufficiently high, 90% confidence level upper limits flux set assuming different power law spectra. To allow crosschecking, two...
Several strong TeV γ-ray flares were detected from Mrk 421 in the years 2000 and 2001 by Tibet III air shower array at a level of statistical significance 5.1 σ. was unprecedentedly active X-ray energies during this period, positive correlation found between change all-sky monitor Rossi X-Ray Timing Explorer flux flux. When power-law energy spectrum for γ-rays source is assumed, spectral index calculated to be -3.24 ± 0.69 most phase 2001. The observed consistent with those obtained via...