Labaciren
Gamma rays from HESS J1849$-$000, a middle-aged TeV pulsar wind nebula (PWN), are observed by the Tibet air shower array and the muon detector array. The detection significance of gamma rays reaches $4.0\, \sigma$ and $4.4\, \sigma$ levels…
HESS J1843$-$033 is a very-high-energy gamma-ray source whose origin remains unidentified. This work presents, for the first time, the energy spectrum of gamma rays beyond $100\, {\rm TeV}$ from the HESS J1843$-$033 region using the data…
Cosmic rays (protons and other atomic nuclei) are believed to gain energies of petaelectronvolts (PeV) and beyond at astrophysical particle accelerators called 'PeVatrons' inside our Galaxy. Although a characteristic feature of a PeVatron…
We report observations of gamma-ray emissions with energies in the 100 TeV energy region from the Cygnus region in our Galaxy. Two sources are significantly detected in the directions of the Cygnus OB1 and OB2 associations. Based on their…
We report, for the first time, the long-awaited detection of diffuse gamma rays with energies between 100 TeV and 1 PeV in the Galactic disk. Particularly, all gamma rays above 398 TeV are observed apart from known TeV gamma-ray sources and…
The amplitude of the Compton-Getting (CG) anisotropy contains the power-law index of the cosmic-ray energy spectrum. Based on this relation and using the Tibet air-shower array data, we measure the cosmic-ray spectral index to be $-3.03 \pm…
We report on the highest energy photons from the Crab Nebula observed by the Tibet air shower array with the underground water-Cherenkov-type muon detector array. Based on the criterion of muon number measured in an air shower, we…
The hadronic interaction of cosmic rays with solar atmosphere can produce high energy gamma rays. The gamma-ray luminosity is correlated both with the flux of primary cosmic rays and the intensity of the solar magnetic field. The gamma rays…
This paper reports on the observation of the sidereal large-scale anisotropy of cosmic rays using data collected by the ARGO-YBJ experiment over 5 years (2008$-$2012). This analysis extends previous work limited to the period from 2008…
We examine the possible influence of Earth-directed coronal mass ejections (ECMEs) on the Sun's shadow in the 3~TeV cosmic-ray intensity observed by the Tibet-III air shower (AS) array. We confirm a clear solar-cycle variation of the…
We analyze the Sun's shadow observed with the Tibet-III air shower array and find that the shadow's center deviates northward (southward) from the optical solar disc center in the "Away" ("Toward") IMF sector. By comparing with numerical…
The ARGO-YBJ experiment, a full coverage extensive air shower (EAS) detector located at high altitude (4300 m a.s.l.) in Tibet, China, has smoothly taken data, with very high stability, since November 2007 to the beginning of 2013. The…
The ARGO-YBJ experiment is a full-coverage air shower detector located at the Yangbajing Cosmic Ray Observatory (Tibet, People's Republic of China, 4300 m a.s.l.). The high altitude, combined with the full-coverage technique, allows the…
We report on a measurement of thermal neutrons, generated by the hadronic component of extensive air showers (EAS), by means of a small array of EN-detectors developed for the PRISMA project (PRImary Spectrum Measurement Array), novel…
We report on the extensive multi-wavelength observations of the blazar Markarian 421 (Mrk 421) covering radio to gamma-rays, during the 4.5 year period of ARGO-YBJ and Fermi common operation time, from August 2008 to February 2013. In…
The measurement of cosmic ray energy spectra, in particular for individual species, is an essential approach in finding their origin. Locating the "knees" of the spectra is an important part of the approach and has yet to be achieved. Here…
The events recorded by ARGO-YBJ in more than five years of data collection have been analyzed to determine the diffuse gamma-ray emission in the Galactic plane at Galactic longitudes 25{\deg} < l < 100{\deg} and Galactic latitudes . The…
The energy spectrum of cosmic Hydrogen and Helium nuclei has been measured, below the so-called "knee", by using a hybrid experiment with a wide field-of-view Cherenkov telescope and the Resistive Plate Chamber (RPC) array of the ARGO-YBJ…
We report on a clear solar-cycle variation of the Sun's shadow in the 10 TeV cosmic-ray flux observed by the Tibet air shower array during a full solar cycle from 1996 to 2009. In order to clarify the physical implications of the observed…
The sun blocks cosmic ray particles from outside the solar system, forming a detectable shadow in the sky map of cosmic rays detected by the ARGO-YBJ experiment in Tibet. Because the cosmic ray particles are positive charged, the magnetic…