J. Kushida
A5085492416- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Dark Matter and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Astrophysical Phenomena and Observations
- Particle Detector Development and Performance
- Neutrino Physics Research
- Pulsars and Gravitational Waves Research
- Particle Accelerators and Free-Electron Lasers
- Astronomical Observations and Instrumentation
- Astronomy and Astrophysical Research
- Particle physics theoretical and experimental studies
- Radiation Detection and Scintillator Technologies
- Cosmology and Gravitation Theories
- Solar and Space Plasma Dynamics
- Gyrotron and Vacuum Electronics Research
- Adaptive optics and wavefront sensing
- Geophysics and Gravity Measurements
- Stellar, planetary, and galactic studies
- Galaxies: Formation, Evolution, Phenomena
- Calibration and Measurement Techniques
- Noncommutative and Quantum Gravity Theories
- Photocathodes and Microchannel Plates
- Radiation Therapy and Dosimetry
- Computational Physics and Python Applications
Tokai University
2016-2025
Universitat de Barcelona
2021-2024
Instituto de Astrofísica de Canarias
2017-2024
Universidad de La Laguna
2017-2024
Institut d'Estudis Espacials de Catalunya
2024
Max Planck Institute for Physics
2011-2023
TU Dortmund University
2023
Foundation for Research and Technology Hellas
2023
University of Siena
2023
Boston University
2023
We present the first joint analysis of gamma-ray data from MAGIC Cherenkov telescopes and Fermi Large Area Telescope (LAT) to search for signals dark matter annihilation in dwarf satellite galaxies. combine 158 hours Segue 1 observations with 6-year 15 galaxies by -LAT. obtain limits on cross-section particle masses between 10 GeV 100 TeV—the widest mass range ever explored a single analysis. These improve previously published -LAT results up factor two at certain masses. Our new inclusive...
Abstract A neutrino with energy ∼290 TeV, IceCube-170922A, was detected in coincidence the BL Lac object TXS 0506+056 during enhanced gamma-ray activity, chance being rejected at ∼3 σ level. We monitored very-high-energy (VHE) band Major Atmospheric Gamma-ray Imaging Cherenkov (MAGIC) telescopes for ∼41 hr from 1.3 to 40.4 days after detection. Day-timescale variability is clearly resolved. interpret quasi-simultaneous and broadband electromagnetic observations a novel one-zone...
Supermassive black holes with masses of millions to billions solar are commonly found in the centers galaxies. Astronomers seek image jet formation using radio interferometry, but still suffer from insufficient angular resolution. An alternative method resolve small structures is measure time variability their emission. Here, we report on gamma-ray observations galaxy IC 310 obtained MAGIC telescopes revealing doubling scales faster than 4.8 min. Causality constrains size emission region be...
We present the results of stereoscopic observations satellite galaxy Segue 1 with MAGIC Telescopes, carried out between 2011 and 2013. With almost 160 hours good-quality data, this is deepest observational campaign on any dwarf performed so far in very high energy range electromagnetic spectrum. search large data sample for signals dark matter particles mass 100 GeV 20 TeV. For we use full likelihood analysis method, which provides optimal sensitivity to characteristic gamma-ray spectral...
Aims. We investigate the extension of very high-energy spectral tail Crab Pulsar at energies above 400 GeV.
We performed a 4.5-month multi-instrument campaign (from radio to VHE gamma rays) on Mrk421 between January 2009 and June 2009, which included VLBA, F-GAMMA, GASP-WEBT, Swift, RXTE, Fermi-LAT, MAGIC, Whipple, among other instruments collaborations. was found in its typical (non-flaring) activity state, with flux of about half that the Crab Nebula, yet light curves show significant variability at all wavelengths, highest being X-rays. determined power spectral densities (PSD) most wavelengths...
The flat-spectrum radio quasar PKS 1441+25 at a redshift of z = 0.940 is detected between 40 and 250 GeV with significance 25.5σ using the MAGIC telescopes. Together gravitationally lensed blazar QSO B0218+357 (z 0.944), most distant very high energy (VHE) to date. observations were triggered by an outburst in 2015 April seen energies Large Area Telescope on board Fermi. Multi-wavelength suggest subdivision state into two distinct flux states. In band covered MAGIC, variability timescale...
It is widely believed that the bulk of Galactic cosmic rays are accelerated in supernova remnants (SNRs). However, no observational evidence presence particles PeV energies SNRs has yet been found. The young historical SNR Cassiopeia A (Cas A) appears as one best candidates to study acceleration processes. Between December 2014 and October 2016 we observed Cas with MAGIC telescopes, accumulating 158 hours good-quality data. We derived spectrum source from 100 GeV 10 TeV. also analysed...
We present a measurement of the extragalactic background light (EBL) based on joint likelihood analysis 32 gamma-ray spectra for 12 blazars in redshift range z = 0.03 to 0.944, obtained by MAGIC telescopes and Fermi-LAT. The EBL is part diffuse radiation spanning ultraviolet, visible infrared bands. Major contributors are emitted stars through history universe, fraction it which was absorbed dust galaxies re-emitted at longer wavelengths. can be studied indirectly its effect very-high energy...
On January 14, 2019, the Major Atmospheric Gamma Imaging Cherenkov telescopes detected GRB 190114C above 0.2 TeV, recording most energetic photons ever observed from a gamma-ray burst. We use this unique observation to probe an energy dependence of speed light in vacuo for as predicted by several quantum gravity models. Based on set assumptions possible intrinsic spectral and temporal evolution, we obtain competitive lower limits quadratic leading order modification.
Extended and delayed emission around distant TeV sources induced by the effects of propagation gamma rays through intergalactic medium can be used for measurement magnetic field (IGMF). We search GeV from hard-spectrum blazar 1ES 0229+200 with goal to detect or constrain IGMF-dependent secondary flux generated during medium. analyze most recent MAGIC observations over a 5 year time span complement them historic data H.E.S.S. VERITAS telescopes along 12-year long exposure Fermi/LAT telescope....
We have detected sub-TeV gamma-ray emission from the direction of Galactic center (GC) using CANGAROO-II Imaging Atmospheric Cerenkov Telescope. a statistically significant excess at energies greater than 250 GeV. The flux was 1 order magnitude lower that Crab Nebula TeV with soft spectrum proportional to E-4.6±0.5. signal centroid is consistent GC direction, and observed profile pointlike source. Our data suggest GeV source 3EG J1746-2851 identical this source, we study combined spectra...
Among more than fifty blazars detected in very high energy (VHE, E>100GeV) gamma-rays, only three belong to the subclass of Flat Spectrum Radio Quasars (FSRQs). MAGIC observed FSRQ PKS 1510-089 February-April 2012 during a activity state (HE, E>100 MeV) gamma-ray band by AGILE and Fermi. observations result detection source with significance 6.0 sigma. In agreement previous VHE source, we find no statistically significant variability daily, weekly or monthly time scales. The other two...
We report on the observation of $\gamma$-rays above 25\,GeV from Crab pulsar (PSR B0532+21) using MAGIC I telescope. Two data sets observations during winter period 2007/2008 and 2008/2009 are used. In order to discuss spectral shape 100\,MeV 100\,GeV, one year public {\it Fermi} Large Area Telescope ({\it Fermi}-LAT) also analyzed complement data. The extrapolation exponential cutoff spectrum determined with Fermi-LAT is inconsistent measurements, which requires a modification standard...
We use 73 h of stereoscopic data taken with the MAGIC telescopes to investigate very high-energy (VHE) gamma-ray emission Crab pulsar. Our show a highly significant pulsed signal in energy range from 50 400 GeV both main pulse (P1) and interpulse (P2) phase regions. provide widest spectra date VHE components peaks, these extend satellite-borne observatories. The good resolution background rejection system allows us cross-check correctness each spectral point pulsar by comparison...
Context. QSO B0218+357 is a gravitationally lensed blazar located at redshift of 0.944. The gravitational lensing splits the emitted radiation into two components that are spatially indistinguishable by gamma-ray instruments, but separated 10–12 day delay. In July 2014, experienced violent flare observed Fermi-LAT and followed MAGIC telescopes.
Context. Because of its proximity, Mrk 421 is one the best sources on which to study nature BL Lac objects. Its proximity allows us characterize broadband spectral energy distribution (SED).